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  • JS regular expression to find a substring surrounded by double quotes

    - by 2619
    I need to find a substring surrounded by double quotes, for example, like "test", "te\"st" or "", but not """ neither "\". To achieve this, which is the best way to go for it in the following 1) /".*"/g 2) /"[^"\\]*(?:\\[\S\s][^"\\]*)*"/g 3) /"(?:\\?[\S\s])*?"/g 4) /"([^"\\]*("|\\[\S\s]))+/g I was asked this question yesterday during an interview, and would like to know the answer for future reference.

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  • F# Library in Silverlight Application?

    - by cam
    I have an F# library in the same solution as a Silverlight (C#) project that I'd like to use the library in. When I try to add a reference to the library project, it says I can only add Silverlight references. How can I make this F# library compatible with my Silverlight project? I'm using Visual Studio 2010.

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  • Namespace and class conflict(?)

    - by dan gibson
    This is a bad title for the question, but I'm not quite sure of a better one. I have a namespace called Globals with a class X in it. I also have a class called Globals. When I try to access Globals.X.StaticMember it tries to access the class Globals.X and complains that X doesn't exist. How do I reference the namespace Globals - ie ::Globals.X.StaticMember (:: doesn't compile).

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  • Restrict a generic type

    - by Water Cooler v2
    I want to restrict the generic type parameter to: 1) either that of a certain user defined reference type; OR 2) any of the primitive types in the CLR; How do I say something to the effect of: interface IDataManager<T>: IDataManager where T: IDataObject, T: ValueType

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  • Building applications with WPF, MVVM and Prism(aka CAG)

    - by skjagini
    In this article I am going to walk through an application using WPF and Prism (aka composite application guidance, CAG) which simulates engaging a taxi (cab).  The rules are simple, the app would have3 screens A login screen to authenticate the user An information screen. A screen to engage the cab and roam around and calculating the total fare Metered Rate of Fare The meter is required to be engaged when a cab is occupied by anyone $3.00 upon entry $0.35 for each additional unit The unit fare is: one-fifth of a mile, when the cab is traveling at 6 miles an hour or more; or 60 seconds when not in motion or traveling at less than 12 miles per hour. Night surcharge of $.50 after 8:00 PM & before 6:00 AM Peak hour Weekday Surcharge of $1.00 Monday - Friday after 4:00 PM & before 8:00 PM New York State Tax Surcharge of $.50 per ride. Example: Friday (2010-10-08) 5:30pm Start at Lexington Ave & E 57th St End at Irving Pl & E 15th St Start = $3.00 Travels 2 miles at less than 6 mph for 15 minutes = $3.50 Travels at more than 12 mph for 5 minutes = $1.75 Peak hour Weekday Surcharge = $1.00 (ride started at 5:30 pm) New York State Tax Surcharge = $0.50 Before we dive into the app, I would like to give brief description about the framework.  If you want to jump on to the source code, scroll all the way to the end of the post. MVVM MVVM pattern is in no way related to the usage of PRISM in your application and should be considered if you are using WPF irrespective of PRISM or not. Lets say you are not familiar with MVVM, your typical UI would involve adding some UI controls like text boxes, a button, double clicking on the button,  generating event handler, calling a method from business layer and updating the user interface, it works most of the time for developing small scale applications. The problem with this approach is that there is some amount of code specific to business logic wrapped in UI specific code which is hard to unit test it, mock it and MVVM helps to solve the exact problem. MVVM stands for Model(M) – View(V) – ViewModel(VM),  based on the interactions with in the three parties it should be called VVMM,  MVVM sounds more like MVC (Model-View-Controller) so the name. Why it should be called VVMM: View – View Model - Model WPF allows to create user interfaces using XAML and MVVM takes it to the next level by allowing complete separation of user interface and business logic. In WPF each view will have a property, DataContext when set to an instance of a class (which happens to be your view model) provides the data the view is interested in, i.e., view interacts with view model and at the same time view model interacts with view through DataContext. Sujith, if view and view model are interacting directly with each other how does MVVM is helping me separation of concerns? Well, the catch is DataContext is of type Object, since it is of type object view doesn’t know exact type of view model allowing views and views models to be loosely coupled. View models aggregate data from models (data access layer, services, etc) and make it available for views through properties, methods etc, i.e., View Models interact with Models. PRISM Prism is provided by Microsoft Patterns and Practices team and it can be downloaded from codeplex for source code,  samples and documentation on msdn.  The name composite implies, to compose user interface from different modules (views) without direct dependencies on each other, again allowing  loosely coupled development. Well Sujith, I can already do that with user controls, why shall I learn another framework?  That’s correct, you can decouple using user controls, but you still have to manage some amount of coupling, like how to do you communicate between the controls, how do you subscribe/unsubscribe, loading/unloading views dynamically. Prism is not a replacement for user controls, provides the following features which greatly help in designing the composite applications. Dependency Injection (DI)/ Inversion of Control (IoC) Modules Regions Event Aggregator  Commands Simply put, MVVM helps building a single view and Prism helps building an application using the views There are other open source alternatives to Prism, like MVVMLight, Cinch, take a look at them as well. Lets dig into the source code.  1. Solution The solution is made of the following projects Framework: Holds the common functionality in building applications using WPF and Prism TaxiClient: Start up project, boot strapping and app styling TaxiCommon: Helps with the business logic TaxiModules: Holds the meat of the application with views and view models TaxiTests: To test the application 2. DI / IoC Dependency Injection (DI) as the name implies refers to injecting dependencies and Inversion of Control (IoC) means the calling code has no direct control on the dependencies, opposite of normal way of programming where dependencies are passed by caller, i.e inversion; aside from some differences in terminology the concept is same in both the cases. The idea behind DI/IoC pattern is to reduce the amount of direct coupling between different components of the application, the higher the dependency the more tightly coupled the application resulting in code which is hard to modify, unit test and mock.  Initializing Dependency Injection through BootStrapper TaxiClient is the starting project of the solution and App (App.xaml)  is the starting class that gets called when you run the application. From the App’s OnStartup method we will invoke BootStrapper.   namespace TaxiClient { /// <summary> /// Interaction logic for App.xaml /// </summary> public partial class App : Application { protected override void OnStartup(StartupEventArgs e) { base.OnStartup(e);   (new BootStrapper()).Run(); } } } BootStrapper is your contact point for initializing the application including dependency injection, creating Shell and other frameworks. We are going to use Unity for DI and there are lot of open source DI frameworks like Spring.Net, StructureMap etc with different feature set  and you can choose a framework based on your preferences. Note that Prism comes with in built support for Unity, for example we are deriving from UnityBootStrapper in our case and for any other DI framework you have to extend the Prism appropriately   namespace TaxiClient { public class BootStrapper: UnityBootstrapper { protected override IModuleCatalog CreateModuleCatalog() { return new ConfigurationModuleCatalog(); } protected override DependencyObject CreateShell() { Framework.FrameworkBootStrapper.Run(Container, Application.Current.Dispatcher);   Shell shell = new Shell(); shell.ResizeMode = ResizeMode.NoResize; shell.Show();   return shell; } } } Lets take a look into  FrameworkBootStrapper to check out how to register with unity container. namespace Framework { public class FrameworkBootStrapper { public static void Run(IUnityContainer container, Dispatcher dispatcher) { UIDispatcher uiDispatcher = new UIDispatcher(dispatcher); container.RegisterInstance<IDispatcherService>(uiDispatcher);   container.RegisterType<IInjectSingleViewService, InjectSingleViewService>( new ContainerControlledLifetimeManager());   . . . } } } In the above code we are registering two components with unity container. You shall observe that we are following two different approaches, RegisterInstance and RegisterType.  With RegisterInstance we are registering an existing instance and the same instance will be returned for every request made for IDispatcherService   and with RegisterType we are requesting unity container to create an instance for us when required, i.e., when I request for an instance for IInjectSingleViewService, unity will create/return an instance of InjectSingleViewService class and with RegisterType we can configure the life time of the instance being created. With ContaienrControllerLifetimeManager, the unity container caches the instance and reuses for any subsequent requests, without recreating a new instance. Lets take a look into FareViewModel.cs and it’s constructor. The constructor takes one parameter IEventAggregator and if you try to find all references in your solution for IEventAggregator, you will not find a single location where an instance of EventAggregator is passed directly to the constructor. The compiler still finds an instance and works fine because Prism is already configured when used with Unity container to return an instance of EventAggregator when requested for IEventAggregator and in this particular case it is called constructor injection. public class FareViewModel:ObservableBase, IDataErrorInfo { ... private IEventAggregator _eventAggregator;   public FareViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; InitializePropertyNames(); InitializeModel(); PropertyChanged += OnPropertyChanged; } ... 3. Shell Shells are very similar in operation to Master Pages in asp.net or MDI in Windows Forms. And shells contain regions which display the views, you can have as many regions as you wish in a given view. You can also nest regions. i.e, one region can load a view which in itself may contain other regions. We have to create a shell at the start of the application and are doing it by overriding CreateShell method from BootStrapper From the following Shell.xaml you shall notice that we have two content controls with Region names as ‘MenuRegion’ and ‘MainRegion’.  The idea here is that you can inject any user controls into the regions dynamically, i.e., a Menu User Control for MenuRegion and based on the user action you can load appropriate view into MainRegion.    <Window x:Class="TaxiClient.Shell" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Regions="clr-namespace:Microsoft.Practices.Prism.Regions;assembly=Microsoft.Practices.Prism" Title="Taxi" Height="370" Width="800"> <Grid Margin="2"> <ContentControl Regions:RegionManager.RegionName="MenuRegion" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" />   <ContentControl Grid.Row="1" Regions:RegionManager.RegionName="MainRegion" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" /> <!--<Border Grid.ColumnSpan="2" BorderThickness="2" CornerRadius="3" BorderBrush="LightBlue" />-->   </Grid> </Window> 4. Modules Prism provides the ability to build composite applications and modules play an important role in it. For example if you are building a Mortgage Loan Processor application with 3 components, i.e. customer’s credit history,  existing mortgages, new home/loan information; and consider that the customer’s credit history component involves gathering data about his/her address, background information, job details etc. The idea here using Prism modules is to separate the implementation of these 3 components into their own visual studio projects allowing to build components with no dependency on each other and independently. If we need to add another component to the application, the component can be developed by in house team or some other team in the organization by starting with a new Visual Studio project and adding to the solution at the run time with very little knowledge about the application. Prism modules are defined by implementing the IModule interface and each visual studio project to be considered as a module should implement the IModule interface.  From the BootStrapper.cs you shall observe that we are overriding the method by returning a ConfiguratingModuleCatalog which returns the modules that are registered for the application using the app.config file  and you can also add module using code. Lets take a look into configuration file.   <?xml version="1.0"?> <configuration> <configSections> <section name="modules" type="Microsoft.Practices.Prism.Modularity.ModulesConfigurationSection, Microsoft.Practices.Prism"/> </configSections> <modules> <module assemblyFile="TaxiModules.dll" moduleType="TaxiModules.ModuleInitializer, TaxiModules" moduleName="TaxiModules"/> </modules> </configuration> Here we are adding TaxiModules project to our solution and TaxiModules.ModuleInitializer implements IModule interface   5. Module Mapper With Prism modules you can dynamically add or remove modules from the regions, apart from that Prism also provides API to control adding/removing the views from a region within the same module. Taxi Information Screen: Engage the Taxi Screen: The sample application has two screens, ‘Taxi Information’ and ‘Engage the Taxi’ and they both reside in same module, TaxiModules. ‘Engage the Taxi’ is again made of two user controls, FareView on the left and TotalView on the right. We have created a Shell with two regions, MenuRegion and MainRegion with menu loaded into MenuRegion. We can create a wrapper user control called EngageTheTaxi made of FareView and TotalView and load either TaxiInfo or EngageTheTaxi into MainRegion based on the user action. Though it will work it tightly binds the user controls and for every combination of user controls, we need to create a dummy wrapper control to contain them. Instead we can apply the principles we learned so far from Shell/regions and introduce another template (LeftAndRightRegionView.xaml) made of two regions Region1 (left) and Region2 (right) and load  FareView and TotalView dynamically.  To help with loading of the views dynamically I have introduce an helper an interface, IInjectSingleViewService,  idea suggested by Mike Taulty, a must read blog for .Net developers. using System; using System.Collections.Generic; using System.ComponentModel;   namespace Framework.PresentationUtility.Navigation {   public interface IInjectSingleViewService : INotifyPropertyChanged { IEnumerable<CommandViewDefinition> Commands { get; } IEnumerable<ModuleViewDefinition> Modules { get; }   void RegisterViewForRegion(string commandName, string viewName, string regionName, Type viewType); void ClearViewFromRegion(string viewName, string regionName); void RegisterModule(string moduleName, IList<ModuleMapper> moduleMappers); } } The Interface declares three methods to work with views: RegisterViewForRegion: Registers a view with a particular region. You can register multiple views and their regions under one command.  When this particular command is invoked all the views registered under it will be loaded into their regions. ClearViewFromRegion: To unload a specific view from a region. RegisterModule: The idea is when a command is invoked you can load the UI with set of controls in their default position and based on the user interaction, you can load different contols in to different regions on the fly.  And it is supported ModuleViewDefinition and ModuleMappers as shown below. namespace Framework.PresentationUtility.Navigation { public class ModuleViewDefinition { public string ModuleName { get; set; } public IList<ModuleMapper> ModuleMappers; public ICommand Command { get; set; } }   public class ModuleMapper { public string ViewName { get; set; } public string RegionName { get; set; } public Type ViewType { get; set; } } } 6. Event Aggregator Prism event aggregator enables messaging between components as in Observable pattern, Notifier notifies the Observer which receives notification it is interested in. When it comes to Observable pattern, Observer has to unsubscribes for notifications when it no longer interested in notifications, which allows the Notifier to remove the Observer’s reference from it’s local cache. Though .Net has managed garbage collection it cannot remove inactive the instances referenced by an active instance resulting in memory leak, keeping the Observers in memory as long as Notifier stays in memory.  Developers have to be very careful to unsubscribe when necessary and it often gets overlooked, to overcome these problems Prism Event Aggregator uses weak references to cache the reference (Observer in this case)  and releases the reference (memory) once the instance goes out of scope. Using event aggregator is very simple, declare a generic type of CompositePresenationEvent by inheriting from it. using Microsoft.Practices.Prism.Events; using TaxiCommon.BAO;   namespace TaxiCommon.CompositeEvents { public class TaxiOnMoveEvent:CompositePresentationEvent<TaxiOnMove> { } }   TaxiOnMove.cs includes the properties which we want to exchange between the parties, FareView and TotalView. using System;   namespace TaxiCommon.BAO { public class TaxiOnMove { public TimeSpan MinutesAtTweleveMPH { get; set; } public double MilesAtSixMPH { get; set; } } }   Lets take a look into FareViewodel (Notifier) and how it raises the event.  Here we are raising the event by getting the event through GetEvent<..>() and publishing it with the payload private void OnAddMinutes(object obj) { TaxiOnMove payload = new TaxiOnMove(); if(MilesAtSixMPH != null) payload.MilesAtSixMPH = MilesAtSixMPH.Value; if(MinutesAtTweleveMPH != null) payload.MinutesAtTweleveMPH = new TimeSpan(0,0,MinutesAtTweleveMPH.Value,0);   _eventAggregator.GetEvent<TaxiOnMoveEvent>().Publish(payload); ResetMinutesAndMiles(); } And TotalViewModel(Observer) subscribes to notifications by getting the event through GetEvent<..>() namespace TaxiModules.ViewModels { public class TotalViewModel:ObservableBase { .... private IEventAggregator _eventAggregator;   public TotalViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator; ... }   private void SubscribeToEvents() { _eventAggregator.GetEvent<TaxiStartedEvent>() .Subscribe(OnTaxiStarted, ThreadOption.UIThread,false,(filter) => true); _eventAggregator.GetEvent<TaxiOnMoveEvent>() .Subscribe(OnTaxiMove, ThreadOption.UIThread, false, (filter) => true); _eventAggregator.GetEvent<TaxiResetEvent>() .Subscribe(OnTaxiReset, ThreadOption.UIThread, false, (filter) => true); }   ... private void OnTaxiMove(TaxiOnMove taxiOnMove) { OnMoveFare fare = new OnMoveFare(taxiOnMove); Fares.Add(fare); SetTotalFare(new []{fare}); }   .... 7. MVVM through example In this section we are going to look into MVVM implementation through example.  I have all the modules declared in a single project, TaxiModules, again it is not necessary to have them into one project. Once the user logs into the application, will be greeted with the ‘Engage the Taxi’ screen which is made of two user controls, FareView.xaml and TotalView.Xaml. As you can see from the solution explorer, each of them have their own code behind files and  ViewModel classes, FareViewMode.cs, TotalViewModel.cs Lets take a look in to the FareView and how it interacts with FareViewModel using MVVM implementation. FareView.xaml acts as a view and FareViewMode.cs is it’s view model. The FareView code behind class   namespace TaxiModules.Views { /// <summary> /// Interaction logic for FareView.xaml /// </summary> public partial class FareView : UserControl { public FareView(FareViewModel viewModel) { InitializeComponent(); this.Loaded += (s, e) => { this.DataContext = viewModel; }; } } } The FareView is bound to FareViewModel through the data context  and you shall observe that DataContext is of type Object, i.e. the FareView doesn’t really know the type of ViewModel (FareViewModel). This helps separation of View and ViewModel as View and ViewModel are independent of each other, you can bind FareView to FareViewModel2 as well and the application compiles just fine. Lets take a look into FareView xaml file  <UserControl x:Class="TaxiModules.Views.FareView" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:Toolkit="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit" xmlns:Commands="clr-namespace:Microsoft.Practices.Prism.Commands;assembly=Microsoft.Practices.Prism"> <Grid Margin="10" > ....   <Border Style="{DynamicResource innerBorder}" Grid.Row="0" Grid.Column="0" Grid.RowSpan="11" Grid.ColumnSpan="2" Panel.ZIndex="1"/>   <Label Grid.Row="0" Content="Engage the Taxi" Style="{DynamicResource innerHeader}"/> <Label Grid.Row="1" Content="Select the State"/> <ComboBox Grid.Row="1" Grid.Column="1" ItemsSource="{Binding States}" Height="auto"> <ComboBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding Name}"/> </DataTemplate> </ComboBox.ItemTemplate> <ComboBox.SelectedItem> <Binding Path="SelectedState" Mode="TwoWay"/> </ComboBox.SelectedItem> </ComboBox> <Label Grid.Row="2" Content="Select the Date of Entry"/> <Toolkit:DatePicker Grid.Row="2" Grid.Column="1" SelectedDate="{Binding DateOfEntry, ValidatesOnDataErrors=true}" /> <Label Grid.Row="3" Content="Enter time 24hr format"/> <TextBox Grid.Row="3" Grid.Column="1" Text="{Binding TimeOfEntry, TargetNullValue=''}"/> <Button Grid.Row="4" Grid.Column="1" Content="Start the Meter" Commands:Click.Command="{Binding StartMeterCommand}" />   <Label Grid.Row="5" Content="Run the Taxi" Style="{DynamicResource innerHeader}"/> <Label Grid.Row="6" Content="Number of Miles &lt;@6mph"/> <TextBox Grid.Row="6" Grid.Column="1" Text="{Binding MilesAtSixMPH, TargetNullValue='', ValidatesOnDataErrors=true}"/> <Label Grid.Row="7" Content="Number of Minutes @12mph"/> <TextBox Grid.Row="7" Grid.Column="1" Text="{Binding MinutesAtTweleveMPH, TargetNullValue=''}"/> <Button Grid.Row="8" Grid.Column="1" Content="Add Minutes and Miles " Commands:Click.Command="{Binding AddMinutesCommand}"/> <Label Grid.Row="9" Content="Other Operations" Style="{DynamicResource innerHeader}"/> <Button Grid.Row="10" Grid.Column="1" Content="Reset the Meter" Commands:Click.Command="{Binding ResetCommand}"/>   </Grid> </UserControl> The highlighted code from the above code shows data binding, for example ComboBox which displays list of states has it’s ItemsSource bound to States property, with DataTemplate bound to Name and SelectedItem  to SelectedState. You might be wondering what are all these properties and how it is able to bind to them.  The answer lies in data context, i.e., when you bound a control, WPF looks for data context on the root object (Grid in this case) and if it can’t find data context it will look into root’s root, i.e. FareView UserControl and it is bound to FareViewModel.  Each of those properties have be declared on the ViewModel for the View to bind correctly. To put simply, View is bound to ViewModel through data context of type object and every control that is bound on the View actually binds to the public property on the ViewModel. Lets look into the ViewModel code (the following code is not an exact copy of FareViewMode.cs, pasted relevant code for this section)   namespace TaxiModules.ViewModels { public class FareViewModel:ObservableBase, IDataErrorInfo { public List<USState> States { get { return USStates.StateList; } }   public USState SelectedState { get { return _selectedState; } set { _selectedState = value; RaisePropertyChanged(_selectedStatePropertyName); } }   public DateTime? DateOfEntry { get { return _dateOfEntry; } set { _dateOfEntry = value; RaisePropertyChanged(_dateOfEntryPropertyName); } }   public TimeSpan? TimeOfEntry { get { return _timeOfEntry; } set { _timeOfEntry = value; RaisePropertyChanged(_timeOfEntryPropertyName); } }   public double? MilesAtSixMPH { get { return _milesAtSixMPH; } set { _milesAtSixMPH = value; RaisePropertyChanged(_distanceAtSixMPHPropertyName); } }   public int? MinutesAtTweleveMPH { get { return _minutesAtTweleveMPH; } set { _minutesAtTweleveMPH = value; RaisePropertyChanged(_minutesAtTweleveMPHPropertyName); } }   public ICommand StartMeterCommand { get { if(_startMeterCommand == null) { _startMeterCommand = new DelegateCommand<object>(OnStartMeter, CanStartMeter); } return _startMeterCommand; } }   public ICommand AddMinutesCommand { get { if(_addMinutesCommand == null) { _addMinutesCommand = new DelegateCommand<object>(OnAddMinutes, CanAddMinutes); } return _addMinutesCommand; } }   public ICommand ResetCommand { get { if(_resetCommand == null) { _resetCommand = new DelegateCommand<object>(OnResetCommand); } return _resetCommand; } }   } private void OnStartMeter(object obj) { _eventAggregator.GetEvent<TaxiStartedEvent>().Publish( new TaxiStarted() { EngagedOn = DateOfEntry.Value.Date + TimeOfEntry.Value, EngagedState = SelectedState.Value });   _isMeterStarted = true; OnPropertyChanged(this,null); } And views communicate user actions like button clicks, tree view item selections, etc using commands. When user clicks on ‘Start the Meter’ button it invokes the method StartMeterCommand, which calls the method OnStartMeter which publishes the event to TotalViewModel using event aggregator  and TaxiStartedEvent. namespace TaxiModules.ViewModels { public class TotalViewModel:ObservableBase { ... private IEventAggregator _eventAggregator;   public TotalViewModel(IEventAggregator eventAggregator) { _eventAggregator = eventAggregator;   InitializePropertyNames(); InitializeModel(); SubscribeToEvents(); }   public decimal? TotalFare { get { return _totalFare; } set { _totalFare = value; RaisePropertyChanged(_totalFarePropertyName); } } .... private void SubscribeToEvents() { _eventAggregator.GetEvent<TaxiStartedEvent>().Subscribe(OnTaxiStarted, ThreadOption.UIThread,false,(filter) => true); _eventAggregator.GetEvent<TaxiOnMoveEvent>().Subscribe(OnTaxiMove, ThreadOption.UIThread, false, (filter) => true); _eventAggregator.GetEvent<TaxiResetEvent>().Subscribe(OnTaxiReset, ThreadOption.UIThread, false, (filter) => true); }   private void OnTaxiStarted(TaxiStarted taxiStarted) { Fares.Add(new EntryFare()); Fares.Add(new StateTaxFare(taxiStarted)); Fares.Add(new NightSurchargeFare(taxiStarted)); Fares.Add(new PeakHourWeekdayFare(taxiStarted));   SetTotalFare(Fares); }   private void SetTotalFare(IEnumerable<IFare> fares) { TotalFare = (_totalFare ?? 0) + TaxiFareHelper.GetTotalFare(fares); } ....   } }   TotalViewModel subscribes to events, TaxiStartedEvent and rest. When TaxiStartedEvent gets invoked it calls the OnTaxiStarted method which sets the total fare which includes entry fee, state tax, nightly surcharge, peak hour weekday fare.   Note that TotalViewModel derives from ObservableBase which implements the method RaisePropertyChanged which we are invoking in Set of TotalFare property, i.e, once we update the TotalFare property it raises an the event that  allows the TotalFare text box to fetch the new value through the data context. ViewModel is communicating with View through data context and it has no knowledge about View, helping in loose coupling of ViewModel and View.   I have attached the source code (.Net 4.0, Prism 4.0, VS 2010) , download and play with it and don’t forget to leave your comments.  

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  • What&rsquo;s New in ASP.NET 4.0 Part Two: WebForms and Visual Studio Enhancements

    - by Rick Strahl
    In the last installment I talked about the core changes in the ASP.NET runtime that I’ve been taking advantage of. In this column, I’ll cover the changes to the Web Forms engine and some of the cool improvements in Visual Studio that make Web and general development easier. WebForms The WebForms engine is the area that has received most significant changes in ASP.NET 4.0. Probably the most widely anticipated features are related to managing page client ids and of ViewState on WebForm pages. Take Control of Your ClientIDs Unique ClientID generation in ASP.NET has been one of the most complained about “features” in ASP.NET. Although there’s a very good technical reason for these unique generated ids - they guarantee unique ids for each and every server control on a page - these unique and generated ids often get in the way of client-side JavaScript development and CSS styling as it’s often inconvenient and fragile to work with the long, generated ClientIDs. In ASP.NET 4.0 you can now specify an explicit client id mode on each control or each naming container parent control to control how client ids are generated. By default, ASP.NET generates mangled client ids for any control contained in a naming container (like a Master Page, or a User Control for example). The key to ClientID management in ASP.NET 4.0 are the new ClientIDMode and ClientIDRowSuffix properties. ClientIDMode supports four different ClientID generation settings shown below. For the following examples, imagine that you have a Textbox control named txtName inside of a master page control container on a WebForms page. <%@Page Language="C#"      MasterPageFile="~/Site.Master"     CodeBehind="WebForm2.aspx.cs"     Inherits="WebApplication1.WebForm2"  %> <asp:Content ID="content"  ContentPlaceHolderID="content"               runat="server"               ClientIDMode="Static" >       <asp:TextBox runat="server" ID="txtName" /> </asp:Content> The four available ClientIDMode values are: AutoID This is the existing behavior in ASP.NET 1.x-3.x where full naming container munging takes place. <input name="ctl00$content$txtName" type="text"        id="ctl00_content_txtName" /> This should be familiar to any ASP.NET developer and results in fairly unpredictable client ids that can easily change if the containership hierarchy changes. For example, removing the master page changes the name in this case, so if you were to move a block of script code that works against the control to a non-Master page, the script code immediately breaks. Static This option is the most deterministic setting that forces the control’s ClientID to use its ID value directly. No naming container naming at all is applied and you end up with clean client ids: <input name="ctl00$content$txtName"         type="text" id="txtName" /> Note that the name property which is used for postback variables to the server still is munged, but the ClientID property is displayed simply as the ID value that you have assigned to the control. This option is what most of us want to use, but you have to be clear on that because it can potentially cause conflicts with other controls on the page. If there are several instances of the same naming container (several instances of the same user control for example) there can easily be a client id naming conflict. Note that if you assign Static to a data-bound control, like a list child control in templates, you do not get unique ids either, so for list controls where you rely on unique id for child controls, you’ll probably want to use Predictable rather than Static. I’ll write more on this a little later when I discuss ClientIDRowSuffix. Predictable The previous two values are pretty self-explanatory. Predictable however, requires some explanation. To me at least it’s not in the least bit predictable. MSDN defines this value as follows: This algorithm is used for controls that are in data-bound controls. The ClientID value is generated by concatenating the ClientID value of the parent naming container with the ID value of the control. If the control is a data-bound control that generates multiple rows, the value of the data field specified in the ClientIDRowSuffix property is added at the end. For the GridView control, multiple data fields can be specified. If the ClientIDRowSuffix property is blank, a sequential number is added at the end instead of a data-field value. Each segment is separated by an underscore character (_). The key that makes this value a bit confusing is that it relies on the parent NamingContainer’s ClientID to build its own ClientID value. This effectively means that the value is not predictable at all but rather very tightly coupled to the parent naming container’s ClientIDMode setting. For my simple textbox example, if the ClientIDMode property of the parent naming container (Page in this case) is set to “Predictable” you’ll get this: <input name="ctl00$content$txtName" type="text"         id="content_txtName" /> which gives an id that based on walking up to the currently active naming container (the MasterPage content container) and starting the id formatting from there downward. Think of this as a semi unique name that’s guaranteed unique only for the naming container. If, on the other hand, the Page is set to “AutoID” you get the following with Predictable on txtName: <input name="ctl00$content$txtName" type="text"         id="ctl00_content_txtName" /> The latter is effectively the same as if you specified AutoID because it inherits the AutoID naming from the Page and Content Master Page control of the page. But again - predictable behavior always depends on the parent naming container and how it generates its id, so the id may not always be exactly the same as the AutoID generated value because somewhere in the NamingContainer chain the ClientIDMode setting may be set to a different value. For example, if you had another naming container in the middle that was set to Static you’d end up effectively with an id that starts with the NamingContainers id rather than the whole ctl000_content munging. The most common use for Predictable is likely to be for data-bound controls, which results in each data bound item getting a unique ClientID. Unfortunately, even here the behavior can be very unpredictable depending on which data-bound control you use - I found significant differences in how template controls in a GridView behave from those that are used in a ListView control. For example, GridView creates clean child ClientIDs, while ListView still has a naming container in the ClientID, presumably because of the template container on which you can’t set ClientIDMode. Predictable is useful, but only if all naming containers down the chain use this setting. Otherwise you’re right back to the munged ids that are pretty unpredictable. Another property, ClientIDRowSuffix, can be used in combination with ClientIDMode of Predictable to force a suffix onto list client controls. For example: <asp:GridView runat="server" ID="gvItems"              AutoGenerateColumns="false"             ClientIDMode="Static"              ClientIDRowSuffix="Id">     <Columns>     <asp:TemplateField>         <ItemTemplate>             <asp:Label runat="server" id="txtName"                        Text='<%# Eval("Name") %>'                   ClientIDMode="Predictable"/>         </ItemTemplate>     </asp:TemplateField>     <asp:TemplateField>         <ItemTemplate>         <asp:Label runat="server" id="txtId"                     Text='<%# Eval("Id") %>'                     ClientIDMode="Predictable" />         </ItemTemplate>     </asp:TemplateField>     </Columns>  </asp:GridView> generates client Ids inside of a column in the master page described earlier: <td>     <span id="txtName_0">Rick</span> </td> where the value after the underscore is the ClientIDRowSuffix field - in this case “Id” of the item data bound to the control. Note that all of the child controls require ClientIDMode=”Predictable” in order for the ClientIDRowSuffix to be applied, and the parent GridView controls need to be set to Static either explicitly or via Naming Container inheritance to give these simple names. It’s a bummer that ClientIDRowSuffix doesn’t work with Static to produce this automatically. Another real problem is that other controls process the ClientIDMode differently. For example, a ListView control processes the Predictable ClientIDMode differently and produces the following with the Static ListView and Predictable child controls: <span id="ctrl0_txtName_0">Rick</span> I couldn’t even figure out a way using ClientIDMode to get a simple ID that also uses a suffix short of falling back to manually generated ids using <%= %> expressions instead. Given the inconsistencies inside of list controls using <%= %>, ids for the ListView might not be a bad idea anyway. Inherit The final setting is Inherit, which is the default for all controls except Page. This means that controls by default inherit the parent naming container’s ClientIDMode setting. For more detailed information on ClientID behavior and different scenarios you can check out a blog post of mine on this subject: http://www.west-wind.com/weblog/posts/54760.aspx. ClientID Enhancements Summary The ClientIDMode property is a welcome addition to ASP.NET 4.0. To me this is probably the most useful WebForms feature as it allows me to generate clean IDs simply by setting ClientIDMode="Static" on either the page or inside of Web.config (in the Pages section) which applies the setting down to the entire page which is my 95% scenario. For the few cases when it matters - for list controls and inside of multi-use user controls or custom server controls) - I can use Predictable or even AutoID to force controls to unique names. For application-level page development, this is easy to accomplish and provides maximum usability for working with client script code against page controls. ViewStateMode Another area of large criticism for WebForms is ViewState. ViewState is used internally by ASP.NET to persist page-level changes to non-postback properties on controls as pages post back to the server. It’s a useful mechanism that works great for the overall mechanics of WebForms, but it can also cause all sorts of overhead for page operation as ViewState can very quickly get out of control and consume huge amounts of bandwidth in your page content. ViewState can also wreak havoc with client-side scripting applications that modify control properties that are tracked by ViewState, which can produce very unpredictable results on a Postback after client-side updates. Over the years in my own development, I’ve often turned off ViewState on pages to reduce overhead. Yes, you lose some functionality, but you can easily implement most of the common functionality in non-ViewState workarounds. Relying less on heavy ViewState controls and sticking with simpler controls or raw HTML constructs avoids getting around ViewState problems. In ASP.NET 3.x and prior, it wasn’t easy to control ViewState - you could turn it on or off and if you turned it off at the page or web.config level, you couldn’t turn it back on for specific controls. In short, it was an all or nothing approach. With ASP.NET 4.0, the new ViewStateMode property gives you more control. It allows you to disable ViewState globally either on the page or web.config level and then turn it back on for specific controls that might need it. ViewStateMode only works when EnableViewState="true" on the page or web.config level (which is the default). You can then use ViewStateMode of Disabled, Enabled or Inherit to control the ViewState settings on the page. If you’re shooting for minimal ViewState usage, the ideal situation is to set ViewStateMode to disabled on the Page or web.config level and only turn it back on particular controls: <%@Page Language="C#"      CodeBehind="WebForm2.aspx.cs"     Inherits="Westwind.WebStore.WebForm2"        ClientIDMode="Static"                ViewStateMode="Disabled"     EnableViewState="true"  %> <!-- this control has viewstate  --> <asp:TextBox runat="server" ID="txtName"  ViewStateMode="Enabled" />       <!-- this control has no viewstate - it inherits  from parent container --> <asp:TextBox runat="server" ID="txtAddress" /> Note that the EnableViewState="true" at the Page level isn’t required since it’s the default, but it’s important that the value is true. ViewStateMode has no effect if EnableViewState="false" at the page level. The main benefit of ViewStateMode is that it allows you to more easily turn off ViewState for most of the page and enable only a few key controls that might need it. For me personally, this is a perfect combination as most of my WebForm apps can get away without any ViewState at all. But some controls - especially third party controls - often don’t work well without ViewState enabled, and now it’s much easier to selectively enable controls rather than the old way, which required you to pretty much turn off ViewState for all controls that you didn’t want ViewState on. Inline HTML Encoding HTML encoding is an important feature to prevent cross-site scripting attacks in data entered by users on your site. In order to make it easier to create HTML encoded content, ASP.NET 4.0 introduces a new Expression syntax using <%: %> to encode string values. The encoding expression syntax looks like this: <%: "<script type='text/javascript'>" +     "alert('Really?');</script>" %> which produces properly encoded HTML: &lt;script type=&#39;text/javascript&#39; &gt;alert(&#39;Really?&#39;);&lt;/script&gt; Effectively this is a shortcut to: <%= HttpUtility.HtmlEncode( "<script type='text/javascript'>" + "alert('Really?');</script>") %> Of course the <%: %> syntax can also evaluate expressions just like <%= %> so the more common scenario applies this expression syntax against data your application is displaying. Here’s an example displaying some data model values: <%: Model.Address.Street %> This snippet shows displaying data from your application’s data store or more importantly, from data entered by users. Anything that makes it easier and less verbose to HtmlEncode text is a welcome addition to avoid potential cross-site scripting attacks. Although I listed Inline HTML Encoding here under WebForms, anything that uses the WebForms rendering engine including ASP.NET MVC, benefits from this feature. ScriptManager Enhancements The ASP.NET ScriptManager control in the past has introduced some nice ways to take programmatic and markup control over script loading, but there were a number of shortcomings in this control. The ASP.NET 4.0 ScriptManager has a number of improvements that make it easier to control script loading and addresses a few of the shortcomings that have often kept me from using the control in favor of manual script loading. The first is the AjaxFrameworkMode property which finally lets you suppress loading the ASP.NET AJAX runtime. Disabled doesn’t load any ASP.NET AJAX libraries, but there’s also an Explicit mode that lets you pick and choose the library pieces individually and reduce the footprint of ASP.NET AJAX script included if you are using the library. There’s also a new EnableCdn property that forces any script that has a new WebResource attribute CdnPath property set to a CDN supplied URL. If the script has this Attribute property set to a non-null/empty value and EnableCdn is enabled on the ScriptManager, that script will be served from the specified CdnPath. [assembly: WebResource(    "Westwind.Web.Resources.ww.jquery.js",    "application/x-javascript",    CdnPath =  "http://mysite.com/scripts/ww.jquery.min.js")] Cool, but a little too static for my taste since this value can’t be changed at runtime to point at a debug script as needed, for example. Assembly names for loading scripts from resources can now be simple names rather than fully qualified assembly names, which make it less verbose to reference scripts from assemblies loaded from your bin folder or the assembly reference area in web.config: <asp:ScriptManager runat="server" id="Id"          EnableCdn="true"         AjaxFrameworkMode="disabled">     <Scripts>         <asp:ScriptReference          Name="Westwind.Web.Resources.ww.jquery.js"         Assembly="Westwind.Web" />     </Scripts>        </asp:ScriptManager> The ScriptManager in 4.0 also supports script combining via the CompositeScript tag, which allows you to very easily combine scripts into a single script resource served via ASP.NET. Even nicer: You can specify the URL that the combined script is served with. Check out the following script manager markup that combines several static file scripts and a script resource into a single ASP.NET served resource from a static URL (allscripts.js): <asp:ScriptManager runat="server" id="Id"          EnableCdn="true"         AjaxFrameworkMode="disabled">     <CompositeScript          Path="~/scripts/allscripts.js">         <Scripts>             <asp:ScriptReference                    Path="~/scripts/jquery.js" />             <asp:ScriptReference                    Path="~/scripts/ww.jquery.js" />             <asp:ScriptReference            Name="Westwind.Web.Resources.editors.js"                 Assembly="Westwind.Web" />         </Scripts>     </CompositeScript> </asp:ScriptManager> When you render this into HTML, you’ll see a single script reference in the page: <script src="scripts/allscripts.debug.js"          type="text/javascript"></script> All you need to do to make this work is ensure that allscripts.js and allscripts.debug.js exist in the scripts folder of your application - they can be empty but the file has to be there. This is pretty cool, but you want to be real careful that you use unique URLs for each combination of scripts you combine or else browser and server caching will easily screw you up royally. The script manager also allows you to override native ASP.NET AJAX scripts now as any script references defined in the Scripts section of the ScriptManager trump internal references. So if you want custom behavior or you want to fix a possible bug in the core libraries that normally are loaded from resources, you can now do this simply by referencing the script resource name in the Name property and pointing at System.Web for the assembly. Not a common scenario, but when you need it, it can come in real handy. Still, there are a number of shortcomings in this control. For one, the ScriptManager and ClientScript APIs still have no common entry point so control developers are still faced with having to check and support both APIs to load scripts so that controls can work on pages that do or don’t have a ScriptManager on the page. The CdnUrl is static and compiled in, which is very restrictive. And finally, there’s still no control over where scripts get loaded on the page - ScriptManager still injects scripts into the middle of the HTML markup rather than in the header or optionally the footer. This, in turn, means there is little control over script loading order, which can be problematic for control developers. MetaDescription, MetaKeywords Page Properties There are also a number of additional Page properties that correspond to some of the other features discussed in this column: ClientIDMode, ClientTarget and ViewStateMode. Another minor but useful feature is that you can now directly access the MetaDescription and MetaKeywords properties on the Page object to set the corresponding meta tags programmatically. Updating these values programmatically previously required either <%= %> expressions in the page markup or dynamic insertion of literal controls into the page. You can now just set these properties programmatically on the Page object in any Control derived class on the page or the Page itself: Page.MetaKeywords = "ASP.NET,4.0,New Features"; Page.MetaDescription = "This article discusses the new features in ASP.NET 4.0"; Note, that there’s no corresponding ASP.NET tag for the HTML Meta element, so the only way to specify these values in markup and access them is via the @Page tag: <%@Page Language="C#"      CodeBehind="WebForm2.aspx.cs"     Inherits="Westwind.WebStore.WebForm2"      ClientIDMode="Static"                MetaDescription="Article that discusses what's                      new in ASP.NET 4.0"     MetaKeywords="ASP.NET,4.0,New Features" %> Nothing earth shattering but quite convenient. Visual Studio 2010 Enhancements for Web Development For Web development there are also a host of editor enhancements in Visual Studio 2010. Some of these are not Web specific but they are useful for Web developers in general. Text Editors Throughout Visual Studio 2010, the text editors have all been updated to a new core engine based on WPF which provides some interesting new features for various code editors including the nice ability to zoom in and out with Ctrl-MouseWheel to quickly change the size of text. There are many more API options to control the editor and although Visual Studio 2010 doesn’t yet use many of these features, we can look forward to enhancements in add-ins and future editor updates from the various language teams that take advantage of the visual richness that WPF provides to editing. On the negative side, I’ve noticed that occasionally the code editor and especially the HTML and JavaScript editors will lose the ability to use various navigation keys like arrows, back and delete keys, which requires closing and reopening the documents at times. This issue seems to be well documented so I suspect this will be addressed soon with a hotfix or within the first service pack. Overall though, the code editors work very well, especially given that they were re-written completely using WPF, which was one of my big worries when I first heard about the complete redesign of the editors. Multi-Targeting Visual Studio now targets all versions of the .NET framework from 2.0 forward. You can use Visual Studio 2010 to work on your ASP.NET 2, 3.0 and 3.5 applications which is a nice way to get your feet wet with the new development environment without having to make changes to existing applications. It’s nice to have one tool to work in for all the different versions. Multi-Monitor Support One cool feature of Visual Studio 2010 is the ability to drag windows out of the Visual Studio environment and out onto the desktop including onto another monitor easily. Since Web development often involves working with a host of designers at the same time - visual designer, HTML markup window, code behind and JavaScript editor - it’s really nice to be able to have a little more screen real estate to work on each of these editors. Microsoft made a welcome change in the environment. IntelliSense Snippets for HTML and JavaScript Editors The HTML and JavaScript editors now finally support IntelliSense scripts to create macro-based template expansions that have been in the core C# and Visual Basic code editors since Visual Studio 2005. Snippets allow you to create short XML-based template definitions that can act as static macros or real templates that can have replaceable values that can be embedded into the expanded text. The XML syntax for these snippets is straight forward and it’s pretty easy to create custom snippets manually. You can easily create snippets using XML and store them in your custom snippets folder (C:\Users\rstrahl\Documents\Visual Studio 2010\Code Snippets\Visual Web Developer\My HTML Snippets and My JScript Snippets), but it helps to use one of the third-party tools that exist to simplify the process for you. I use SnippetEditor, by Bill McCarthy, which makes short work of creating snippets interactively (http://snippeteditor.codeplex.com/). Note: You may have to manually add the Visual Studio 2010 User specific Snippet folders to this tool to see existing ones you’ve created. Code snippets are some of the biggest time savers and HTML editing more than anything deals with lots of repetitive tasks that lend themselves to text expansion. Visual Studio 2010 includes a slew of built-in snippets (that you can also customize!) and you can create your own very easily. If you haven’t done so already, I encourage you to spend a little time examining your coding patterns and find the repetitive code that you write and convert it into snippets. I’ve been using CodeRush for this for years, but now you can do much of the basic expansion natively for HTML and JavaScript snippets. jQuery Integration Is Now Native jQuery is a popular JavaScript library and recently Microsoft has recently stated that it will become the primary client-side scripting technology to drive higher level script functionality in various ASP.NET Web projects that Microsoft provides. In Visual Studio 2010, the default full project template includes jQuery as part of a new project including the support files that provide IntelliSense (-vsdoc files). IntelliSense support for jQuery is now also baked into Visual Studio 2010, so unlike Visual Studio 2008 which required a separate download, no further installs are required for a rich IntelliSense experience with jQuery. Summary ASP.NET 4.0 brings many useful improvements to the platform, but thankfully most of the changes are incremental changes that don’t compromise backwards compatibility and they allow developers to ease into the new features one feature at a time. None of the changes in ASP.NET 4.0 or Visual Studio 2010 are monumental or game changers. The bigger features are language and .NET Framework changes that are also optional. This ASP.NET and tools release feels more like fine tuning and getting some long-standing kinks worked out of the platform. It shows that the ASP.NET team is dedicated to paying attention to community feedback and responding with changes to the platform and development environment based on this feedback. If you haven’t gotten your feet wet with ASP.NET 4.0 and Visual Studio 2010, there’s no reason not to give it a shot now - the ASP.NET 4.0 platform is solid and Visual Studio 2010 works very well for a brand new release. Check it out. © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

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  • Silverlight Firestarter thoughts, and thanks to one and all!

    - by Dave Campbell
    A few metrics that of course got out of hand, but some may find interesting:   1/2 My share of the MVP of the Year award in February of 2009 with Laurent Bugnion 2 Number of degrees I hold: B.S., M.S. Electrical Engineering 3 Number of years in the U.S. Army 3.5 Number of years SilverlighCream has been posted 4 Number of times awarded MVP 6 Number of professional positions I've worked: Antenna Rigger, Boilermaker, Musician, Electronic Technician, Hardware Engineer, Software Engineer 16 Number of companies I've worked for during my career as an Engineer 19 Age at which I turned my first line of code 28 Age at which I hit the workforce as an Engineer 33 Number of years working as an Engineer 43 Number of years writing code 62 Number of years since instantiation 116 Number of tags to search SilverlightCream with 645 Number of blogs I view to find articles (at this moment) 664 Number of articles tagged wp7dev at SilverlightCream right now 700 Number of Twitter followers for WynApse 981 Number of individual bloggers in the SilverlightCream database 1002 Number of SilverlightCream blogposts 1100 Number of people live in Redmond for the Firestarter (I think) 1428 Number of total blogposts at GeeksWithBlogs (not counting this one) 4200 Number of Feedburner subscribers (approximately) 6500 Number of Twitter followers for SilverlightNews (approximately) 7087 Number of posts tagged and aggregated at SilverlightCream right now 13000 Number of people registered to watch the Firestarter online (I think) The overwhelming feeling I have returning from the Silverlight Firestarter: Priceless There is absolutely no way that I could personally thank everyone that over the last few years has held their hand out and offered me a step up to get to the point that Scott Guthrie called me out in his keynote. So I'm just going to hit the highlights here... Scott Guthrie Thanks for not only being the level you are at Microsoft, but for being so approachable, easy to talk to, willing to help everyone, and above all knowledgable. My first level manager at my last position asked if Visual Studio was a graphics program... and you step up to a laptop at a conference and type "File->New Program" ... 'nuff said... oh yeah, thanks for the shoutout! John Papa Thanks for being a good friend, ramroding the Firestarter, being a great guy to be around, and for the poster... holy crap is that cool. Tim Heuer Thanks for all you did as a great DE in Phoenix, and for helping out so many of us, of course being a great guy, and for the poster as well... I think you and John shared that task. In no order at all my buddy Michael Washington, Laurent Bugnion (the other half of the first Silverlight MVP of the Year) Tim Sneath, Mike Harsh, Chad Campbell and Bryant Likes (from back in the day), Adam Kinney, Jesse Liberty, Jeff Paries, Pete Brown, András Velvárt, David Kelly, Michael Palermo, Scott Cate, Erik Mork, and on and on... don't feel bad if your name didn't appear, I have simply too many supporters to name. Silverlight Firestarter Indeed All the people mentioned here, and all the MVPs knew Silverlight was NOT dead, but because of a very unfortunate circumstance, the popular media opinion became that. Consequently the Firestarter exploded from a laid-back event to a global conference. People worked their ass off getting bits ready and presentations using those bits. All to stem the flow of misinformation. All involved please accept my personal thanks for an absolutely awesome job. I had the priviledge of watching the 'prep' on Wednesday afternoon, and was blown away the first time I saw the 3D demo... and have been blown away every time I've seen it since. Not to mention all the other goodness in Silverlight 5. Yes I hit 1000 on my blog, but more importantly, all of you are blogging and using Silverlight, and Microsoft hit one completely out of the park... no... they knocked it out of the neighborhood with the Firestarter. It was amazing to be there for it, and it will be awesome to use the new bits as we get them. Keep reading, there's tons more to come with Silverlight and SilverlightCream following along behind. As usual, this old hacker is humbled to be allowed to play with all the cool kids... Thanks one and all for everything, and Stay in the 'Light

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  • Windows Phone appointment task

    - by Dennis Vroegop
    Originally posted on: http://geekswithblogs.net/dvroegop/archive/2014/08/10/windows-phone-appointment-task.aspxI am currently working on a new version of my AgeInDays app for Windows Phone. This app calculates how old you are in days (or weeks, depending on your preferences). The inspiration for this app came from my father, who once told me he proposed to my mother when she was 1000 weeks old. That left me wondering: how old in weeks or days am I? And being the geek I am, I wrote an app for it. If you have a Windows Phone, you can find it at http://www.windowsphone.com/en-in/store/app/age-in-days/7ed03603-0e00-4214-ad04-ce56773e5dab A new version of the app was published quite quickly, adding the possibility to mark a date in your agenda when you would have reached a certain age. Of course the logic behind this if extremely simple. Just take a DateTime, populate it with the given date from the DatePicker, then call AddDays(numDays) and voila, you have the date. Now all I had to do was implement a way to store this in the users calendar so he would get a reminder when that date occurred. Luckily, the Windows Phone SDK makes that extremely simple: public void PublishTask(DateTime occuranceDate, string message) { var task = new SaveAppointmentTask() { StartTime = occuranceDate, EndTime = occuranceDate, Subject = message, Location = string.Empty, IsAllDayEvent = true, Reminder = Reminder.None, AppointmentStatus = AppointmentStatus.Free };   task.Show(); }  And that's it. Whenever I call the PublishTask Method an appointment will be made and put in the calendar. Well, not exactly: a template will be made for that appointment and the user will see that template, giving him the option to either discard or save the reminder. The user can also make changes before submitting this to the calendar: it would be useful to be able to change the text in the agenda and that's exactly what this allows you to do. Now, see at the bottom of the screen the option "Occurs". This tiny field is what this post is about. You cannot set it from the code. I want to be able to have repeating items in my agenda. Say for instance you're counting down to a certain date, I want to be able to give you that option as well. However, I cannot. The field "occurs" is not part of the Task you create in code. Of course, you could create a whole series of events yourself. Have the "Occurs" field in your own user interface and make all the appointments. But that's not the same. First, the system doesn't recognize them as part of a series. That means if you want to change the text later on on one of the occurrences it will not ask you if you want to open this one or the whole series. More important however, is that the user has to acknowledge each and every single occurrence and save that into the agenda. Now, I understand why they implemented the system in such a way that the user has to approve an entry. You don't want apps to automatically fill your agenda with messages such as "Remember to pay for my app!". But why not include the "Occurs" option? The user can still opt out if they see this happening. I hope an update will fix this soon. But for now: you just have to countdown to your birthday yourself. My app won't support this.

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  • SQLAuthority News – Android Efficiency Tips and Tricks – Personal Technology Tip #003

    - by pinaldave
    I use my phone for lots of things.  I use it mainly to replace my tablet – I can e-mail, take and edit photos, and do almost everything I can do on a laptop with this phone.  And I am sure that there are many of you out there just like me.  I personally have a Galaxy S3, which uses the Android operating system, and I have decided to feature it as the third installment of my Technology Tips and Tricks series. 1) Shortcut to your favorite contacts on home screen Access your most-called contacts easily from your home screen by holding your finger on any empty spot on the home screen.  A menu will pop up that allows you to choose Shortcuts, and Contact.  You can scroll through your contact list and then just tap on the name of the person you want to be able to dial with a single click. 2) Keep track of your data usage Yes, we all should keep a close eye on our data usage, because it is very easy to go over our limits and then end up with a giant bill at the end of the month.  Never get surprised when you open that mobile phone envelope again.  Go to Settings, then Data Usage, and you can find a quick rundown of your usage, how much data each app uses, and you can even set alarms to let you know when you are nearing the limits.   Better yet, you can set the phone to stop using data when it reaches a certain limit. 3) Bring back Good Grammar We often hear proclamations about the downfall of written language, and how texting abbreviations, misspellings, and lack of punctuation are the root of all evil.  Well, we can show all those doomsdayers that all is not lost by bringing punctuation back to texting.  Usually we leave it off when we text because it takes too long to get to the screen with all the punctuation options.  But now you can hold down the period (or “full stop”) button and a list of all the commonly-used punctuation marks will pop right up. 4) Apps, Apps, Apps and Apps And finally, I cannot end an article about smart phones without including a list of my favorite apps.  Here are a list of my Top 10 Applications on my Android (not counting social media apps). Advanced Task Killer – Keeps my phone snappy by closing un-necessary apps WhatsApp - my favorite alternate to Text SMS Flipboard - my ‘timepass’ moments Skype – keeps me close to friends and family GoogleMaps - I am never lost because of this one thing Amazon Kindle – Books my best friends DropBox - My data always safe Pluralsight Player – Learning never stops for me Samsung Kies Air – Connecting Phone to Computer Chrome – Replacing default browser I have not included any social media applications in the above list, but you can be sure that I am linked to Twitter, Facebook, Google+, LinkedIn, and YouTube. Reference: Pinal Dave (http://blog.SQLAuthority.com)   Filed under: Best Practices, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology Tagged: Android, Personal Technology

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  • Post MIX10 Decompression

    - by Dave Campbell
    With a big dose of reality, I walked into this place this morning and found out "yeah, I really do write .NET web apps and MS Access for a living" :( ... but it pays the bills and I've gotten *way* used to eating 3 times a day :) MIX10 was great, although the buzz didn't seem as big as MIX09, and I'm not sure why. It also seemed like a different crowd and other folks I talked to agreed with that. Of course now I can outwardly admit that the "Windows Phone 7 Series" is programmed with Silverlight ... how cool is that? I've been biting my tongue about that info for over a month! I cloistered myself in Ballroom A for the week, not counting the Keynotes. That's where the phone sessions were located. I tried to collect the full set, but ended up bailing on the last one because it was ending at the time that MIX10 was ending, and I hadn't spent a whole lot of time in 'The Commons'. I met a bunch of folks I've blogged about, or exchanged email with, and that's always fun. Renewed associations with folks I only see once or twice a year and way too long a list and don't want to mention some and leave off others... I did have an opportunity to meet Charles Petzold... wow that was interesting... I got into Windows development through Charles' Programming Windows 3.1 book 'back in the day' ... couldn't find anyone at Honeywell wanted to join my journey, so it was just me and 'Chuck' :) ... read every word of that book more than once... all marked up, tags sticking out of it. And now he's writing a WP7 book ... gotta get it: Free ebook: Programming Windows Phone 7 Series (DRAFT Preview) I went through my Big List-o-BlogsTM last night and it took over 2 hours because of all the new content since MIX10. I've got 90 posts tagged as of 9PM on 3/21. If everybody stopped right now, it would take me 9 days to push what I have now, so you'll have to be patient! I had another event on Thursday that was *extremely* tiring, so I ended up staying over another night. I drove back into the strip on Friday morning to try to find a non-cheesy souvenir for my wife, and didn't find much. Then I went to Blueberry Hill restaurant for 3 eggs, 3 strips of bacon, and 3 awesome potato pancakes. Check them out if you have time! And then hit the road. In case anyone is wondering, the 2-1/2 hour drive I took across Hoover Dam on Sunday afternoon only took 30 minutes on Friday afternoon... that was a more normal trip! I thoroughly enjoyed the time I spent with everyone. Thanks to John Papa and his crew for the great Insider's party on Monday night... the Blues Brothers were a fun surprise and they did a good job! And the swag was great... thanks to all the contributors for a fun evening at their expense! All I can say is stay tuned, go to live.visitmix.com/videos and watch everything, get the phone tools, start working... everything's different and everything's fun... jump in, it's all Silverlight! Stay in the 'Light! Technorati Tags: Silverlight    Silverlight 4    Windows Phone     MIX10

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  • SQLAuthority News – Android Efficiency Tips and Tricks – Personal Technology Tip

    - by pinaldave
    I use my phone for lots of things.  I use it mainly to replace my tablet – I can e-mail, take and edit photos, and do almost everything I can do on a laptop with this phone.  And I am sure that there are many of you out there just like me.  I personally have a Galaxy S3, which uses the Android operating system, and I have decided to feature it as the third installment of my Technology Tips and Tricks series. 1) Shortcut to your favorite contacts on home screen Access your most-called contacts easily from your home screen by holding your finger on any empty spot on the home screen.  A menu will pop up that allows you to choose Shortcuts, and Contact.  You can scroll through your contact list and then just tap on the name of the person you want to be able to dial with a single click. 2) Keep track of your data usage Yes, we all should keep a close eye on our data usage, because it is very easy to go over our limits and then end up with a giant bill at the end of the month.  Never get surprised when you open that mobile phone envelope again.  Go to Settings, then Data Usage, and you can find a quick rundown of your usage, how much data each app uses, and you can even set alarms to let you know when you are nearing the limits.   Better yet, you can set the phone to stop using data when it reaches a certain limit. 3) Bring back Good Grammar We often hear proclamations about the downfall of written language, and how texting abbreviations, misspellings, and lack of punctuation are the root of all evil.  Well, we can show all those doomsdayers that all is not lost by bringing punctuation back to texting.  Usually we leave it off when we text because it takes too long to get to the screen with all the punctuation options.  But now you can hold down the period (or “full stop”) button and a list of all the commonly-used punctuation marks will pop right up. 4) Apps, Apps, Apps and Apps And finally, I cannot end an article about smart phones without including a list of my favorite apps.  Here are a list of my Top 10 Applications on my Android (not counting social media apps). Advanced Task Killer – Keeps my phone snappy by closing un-necessary apps WhatsApp - my favorite alternate to Text SMS Flipboard - my ‘timepass’ moments Skype – keeps me close to friends and family GoogleMaps - I am never lost because of this one thing Amazon Kindle – Books my best friends DropBox - My data always safe Pluralsight Player – Learning never stops for me Samsung Kies Air – Connecting Phone to Computer Chrome – Replacing default browser I have not included any social media applications in the above list, but you can be sure that I am linked to Twitter, Facebook, Google+, LinkedIn, and YouTube. Reference: Pinal Dave (http://blog.SQLAuthority.com)   Filed under: Best Practices, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority News, T SQL, Technology Tagged: Android, Personal Technology

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  • Silverlight Cream for December 16, 2010 -- #1011

    - by Dave Campbell
    In this Issue: John Papa, Tim Heuer, Jeff Blankenburg(-2-, -3-), Jesse Liberty, Jay Kimble, Wei-Meng Lee, Paul Sheriff, Mike Snow(-2-, -3-), Samuel Jack, James Ashley, and Peter Kuhn. Above the Fold: Silverlight: "Animation Texture Creator" Peter Kuhn WP7: "dows Phone from Scratch #13 — Custom Behaviors Part II: ActionTrigger" Jesse Liberty Shoutouts: Awesome blog post by Jesse Liberty about writing in general: Ten Requirements For Tutorials, Videos, Demos and White Papers That Don’t Suck From SilverlightCream.com: 1000 Silverlight Cream Posts and Counting! John Papa has Silverlight TV number 55 up and it's an inverview he did with me the day before the Firestarter in December... thanks John... great job in making me not look stooopid :) Silverlight service release today - 4.0.51204 Tim Heuer announced a service release of Silverlight ... check out his blog for the updates and near the bottom is a link to the developer runtime. What I Learned In WP7 – Issue #3 Jeff Blankenburg has been pushing out tips ... number 3 consisted of 3 good pieces of info for WP7 devs including more info about fonts and a good site for free audio files What I Learned In WP7 – Issue #4 In number 4, Jeff Blankenburg talks about where to get some nice free WP7 icons, and a link to a cool article on getting all sorts of device info What I Learned In WP7 – Issue #5 Number 5 finds Jeff Blankenburg giving up the XAP for a CodeMash sessiondata app... or wait for it to appear in the Marketplace next week. Windows Phone from Scratch #13 — Custom Behaviors Part II: ActionTrigger Wow... Jesse Liberty is up to number 13 in his Windows Phone from scratch series... this time it's part 2 of his Custom Behaviors post, and ActionTriggers specifically. Solving the Storage Problem in WP7 (for CF Developers) Jay Kimble has released his WP7 dropbox client to the wild ... this is cool for loading files at run-time... opens up some ideas for me at least. Building Location Service Apps in Windows Phone 7 Wei-Meng Lee has a big informative post on location services in WP7... getting a Bing Maps API key, getting the data, navigating and manipulating the map, adding pushpins... good stuff Using Xml Files on Windows Phone Paul Sheriff is discussing XML files as a database for your WP7 apps via LINQ to XML. Sample code included. ABC–Win7 App Mike Snow has been busy with Tips of the Day ... he published a children's app for tracing their ABC's and discusses some of the code bits involved. Win7 Mobile Application Bar – AG_E_PARSER_BAD_PROPERTY_VALUE Mike Snow's next post is about the infamous AG_E_PARSER_BAD_PROPERTY_VALUE error or worse in WP7 ... how he got it, and how he fixed it... could save you some hair... Forward Navigation on the Windows Phone Mike Snow's latest post is about forward navigation on the WP7 ... oh wait... there isn't any... check out the post. Day 2 of my “3 days to Build a Windows Phone 7 Game” challenge Samuel Jack details about 9 hours in day 2 of his quest to build an XNA app for WP7 from a cold start. Windows Phone 7 Side Loading James Ashley has a really complete write-up on side-loading apps onto your WP7 device. Don't get excited... this isn't a hack... this is instructions for side-loading using the Microsoft-approved methos, which means a registered device. Animation Texture Creator Remember Peter Kuhn's post the other day about an Animation Texture Creator? ... well today he has some added tweaks and the source code! ... thanks Peter! Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • HP and Microsoft: That&rsquo;s What Friends Are For ?

    - by andrewbrust
    Today, HP pre-announced the second coming out for its recently acquired Palm webOS mobile operating system.  I happen to think webOS is quite good, and when the Palm Pre first came out, I thought it a worthwhile phone.  I was worried though that the platform would never attract the developer mindshare it needed to be competitive, and that turned out to be the case.  But then HP acquired Palm and announced it would be revamping the webOS offering, not only on phones, but also on tablets.  It later announced that it would also use webOS as an embedded solution on HP printers. The timing of this came shortly after HP had announced it would be producing a “Slate” product running Windows 7. After the Palm deal, HP became vague about whether the Windows-powered slate would actually come out.  They did, in fact, bring the Slate 500 to market, but by some accounts, they only built 5000 units. Another recent awkward moment between HP and Microsoft: HP withdrew itself from the Windows Home Server ecosystem.  That one hurt, as they were the dominant OEM there.  But Microsoft’s decision to kill Drive Extender had driven away many parties, not just HP. On Wednesday, HP came out with their TouchPad, and new phone models.  Not a nice thing for Windows Phone 7, but other OEMs are taking a wait and see attitude there too, I suppose.  There was one more zinger though, and it was bigger: HP announced they’d be porting webOS to PCs. No Windows Phone 7? OK. No Windows Home Server?  Whatcha gonna do?  But no Windows 7 either?  From HP?  What comes after that, no ink and toner? Some people think Microsoft’s been around too long to be relevant.  But HP started out making oscilloscopes!  The notion that HP is too cool for Windows school is a it far-fetched.  This is the company that bought EDS. This is the company that bought Compaq.  And Compaq was the company that bought Digital Equipment Corporation.  Somehow, I don’t think the VT 220 outclasses Windows PCs. What could possibly be going on?  My sense is that HP wants to put webOS on PCs that also have Windows, and that people will buy because they have Windows.  And for every one of those sold, HP gets to count, technically speaking, another webOS unit in the install base.  webOS is really nice, as I said.  But being good isn’t good enough when you are trying to get market share.  Number of units shipped matters.  The question is whether counting PCs with webOS installed, but dormant, is helpful to HP’s cause.  Seems like a funny way to account for market share, and a strange way to treat a big partner in Redmond.

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  • F# and the rose-tinted reflection

    - by CliveT
    We're already seeing increasing use of many cores on client desktops. It is a change that has been long predicted. It is not just a change in architecture, but our notions of efficiency in a program. No longer can we focus on the asymptotic complexity of an algorithm by counting the steps that a single core processor would take to execute it. Instead we'll soon be more concerned about the scalability of the algorithm and how well we can increase the performance as we increase the number of cores. This may even lead us to throw away our most efficient algorithms, and switch to less efficient algorithms that scale better. We might even be willing to waste cycles in order to speculatively execute at the algorithm rather than the hardware level. State is the big headache in this parallel world. At the hardware level, main memory doesn't necessarily contain the definitive value corresponding to a particular address. An update to a location might still be held in a CPU's local cache and it might be some time before the value gets propagated. To get the latest value, and the notion of "latest" takes a lot of defining in this world of rapidly mutating state, the CPUs may well need to communicate to decide who has the definitive value of a particular address in order to avoid lost updates. At the user program level, this means programmers will need to lock objects before modifying them, or attempt to avoid the overhead of locking by understanding the memory models at a very deep level. I think it's this need to avoid statefulness that has led to the recent resurgence of interest in functional languages. In the 1980s, functional languages started getting traction when research was carried out into how programs in such languages could be auto-parallelised. Sadly, the impracticality of some of the languages, the overheads of communication during this parallel execution, and rapid improvements in compiler technology on stock hardware meant that the functional languages fell by the wayside. The one thing that these languages were good at was getting rid of implicit state, and this single idea seems like a solution to the problems we are going to face in the coming years. Whether these languages will catch on is hard to predict. The mindset for writing a program in a functional language is really very different from the way that object-oriented problem decomposition happens - one has to focus on the verbs instead of the nouns, which takes some getting used to. There are a number of hybrid functional/object languages that have been becoming more popular in recent times. These half-way houses make it easy to use functional ideas for some parts of the program while still allowing access to the underlying object-focused platform without a great deal of impedance mismatch. One example is F# running on the CLR which, in Visual Studio 2010, has because a first class member of the pack. Inside Visual Studio 2010, the tooling for F# has improved to the point where it is easy to set breakpoints and watch values change while debugging at the source level. In my opinion, it is the tooling support that will enable the widespread adoption of functional languages - without this support, people will put off any transition into the functional world for as long as they possibly can. Without tool support it will make it hard to learn these languages. One tool that doesn't currently support F# is Reflector. The idea of decompiling IL to a functional language is daunting, but F# is potentially so important I couldn't dismiss the idea. As I'm currently developing Reflector 6.5, I thought it wise to take four days just to see how far I could get in doing so, even if it achieved little more than to be clearer on how much was possible, and how long it might take. You can read what happened here, and of the insights it gave us on ways to improve the tool.

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  • Sorry about the wait.

    - by Ratman21
    In the last two days have been trying remove “Iolo System Mechanic Professional” (With anti-virus and FireWall) from 3 of the 5 pc’s we have (3 lap tops and two Desk tops) as it was going to expire on the 13th.   So I could replace them with a free anti-virus (AVG) and just use the windows fire wall. I have been using the same set up on one of my desk tops (XP Pro) for 8 months and one of the Lap tops (Vista) for 5 months.   The problem was that System Mechanic did not want to go. Even after using the uninstall option on the desk top (my main PC, well its that because has the larger of all the PC’s hard drives but, is the oldest and runs XP home) and using Ccleaner to try and remove it.  It was still showing up as there and after I went a head and tried installing AVG and ran it. I found that the TCP/IP module was missing.  So no internet, I had to restore the PC back to the 1st to get the module back and then install AVG (after making sure window firewall was back on. I didn’t check that on the first try). Got the PC back to normal, very late last night. Only one of the two lap tops was easy but, even at that there are still some parts of System Mechanic on it but, AVG and firewall are working.   I may try an hunt down parts of System Mechanic on it and delete them on this lap top. Which was what finally had to do on the one of the Lap tops (also XP Home) as it would not uninstall after I restored the PC back to the 4th. So delete, delete, delete and Ccleaner (one dl file would not delete though). And I just finish installing AVG and now running a scan on the lap top. So all of this took two days (well three counting today). I started late Friday night and just finishing up now.   I only started this switch over after I had finished my Job search for day on Friday.   As for blogging on Tuesday, Wednesday and Thursday, I was busy and by the end of the day was too tired to blog, that and was hung up still on that 2nd dare of The Love Dare. So I cleaned the house, while she was out of the house. I mean, I cleaned, not just vacuumed house I cleaned the kitchen counter tops and the sinks. Did the dishes and some of the laundry over two of the those days.   As to the third day of Love Dare which is “Love is not selfish” and the dare “Whatever you put your time, energy, and money into will become more important to you. It’s hard to care for something you are not investing in. Along with restraining from negative comments, buy your spouse something that says, I was thinking of you today.”   Being on a very limited income, a lot of normal guy buying for girls is out (for one thing, the comment why did you waste our money on flowers, etc, etc, would come up. Not from me though). So that one is on hold till money issues are not a problem (no that does not mean never). The 4th day “Love is thoughtful” and the dare “Contact your spouse sometime during the business of the day. Have no agenda other than asking how he or she is doing and if there is anything you could do for them”.   I did this dare while I was still working with census last week and trying to do the dares. Well I start my CCNA classes Monday the 15th and I move on to the next Love Dare day “Love is not rude”.

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