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• Code Contracts: validating arrays and collections

  - by DigiMortal

  Validating collections before using them is very common task when we use built-in generic types for our collections. In this posting I will show you how to validate collections using code contracts. It is cool how much awful looking code you can avoid using code contracts. Failing code Let’s suppose we have method that calculates sum of all invoices in collection. We have class Invoice and one of properties it has is Sum. I don’t introduce here any complex calculations on invoices because we have another problem to solve in this topic. Here is our code. public static decimal CalculateTotal(IList<Invoice> invoices) {     var sum = invoices.Sum(p => p.Sum);     return sum; } This method is very simple but it fails when invoices list contains at least one null. Of course, we can test if invoice is null but having nulls in lists like this is not good idea – it opens green way for different coding bugs in system. Our goal is to react to bugs ASAP at the nearest place they occur. There is one more way how to make our method fail. It happens when invoices is null. I thing it is also one common bugs during development and it even happens in production environments under some conditions that are usually hardly met. Now let’s protect our little calculation method with code contracts. We need two contracts: invoices cannot be null invoices cannot contain any nulls Our first contract is easy but how to write the second one? Solution: Contract.ForAll Preconditions in code are checked using Contract.Ensures method. This method takes boolean value as argument that sais if contract holds or not. There is also method Contract.ForAll that takes collection and predicate that must hold for that collection. Nice thing is ForAll returns boolean. So, we have very simple solution. public static decimal CalculateTotal(IList<Invoice> invoices) {     Contract.Requires(invoices != null);     Contract.Requires(Contract.ForAll<Invoice>(invoices, p => p != null));       var sum = invoices.Sum(p => p.Sum);     return sum; } And here are some lines of code you can use to test the contracts quickly. var invoices = new List<Invoice>(); invoices.Add(new Invoice()); invoices.Add(null); invoices.Add(new Invoice()); //CalculateTotal(null); CalculateTotal(invoices); If your code is covered with unit tests then I suggest you to write tests to check that these contracts hold for every code run. Conclusion Although it seemed at first place that checking all elements in collection may end up with for-loops that does not look so nice we were able to solve our problem nicely. ForAll method of contract class offered us simple mechanism to check collections and it does it smoothly the code-contracts-way. P.S. I suggest you also read devlicio.us blog posting Validating Collections with Code Contracts by Derik Whittaker.

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• Join the Dark Side of Visual Studio 2010

  - by InfinitiesLoop

  Hard to believe it’s been so long, but it was almost 4 years ago when I published Join the Dark Side of Visual Studio . That was when a lot of people were still using VS2003, and importing and exporting environment settings required a custom add-in, VSStyler, which has since fallen off the planet and is hard to find (link, anyone? Let me know). Three versions of VS later, and I’m still using and loving the dark side. Pleased, I am (haha). In fact, that article for one reason or another is still one...(read more)

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• Distinct operator in Linq

  - by Jalpesh P. Vadgama

  Linq operator provides great flexibility and easy way of coding. Let’s again take one more example of distinct operator. As name suggest it will find the distinct elements from IEnumerable. Let’s take an example of array in console application and then we will again print array to see is it working or not. Below is the code for that. In this application I have integer array which contains duplicate elements and then I will apply distinct operator to this and then I will print again result of distinct operators to actually see whether its working or not. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Experiment { class Program { static void Main(string[] args) { int[] intArray = { 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5 }; var uniqueIntegers = intArray.Distinct(); foreach (var uInteger in uniqueIntegers) { Console.WriteLine(uInteger); } Console.ReadKey(); } } } Below is output as expected.. That’s cool..Stay tuned for more.. Happy programming. Technorati Tags: Linq,Distinct

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• WCF Data Service Pipeline

  - by Daniel Cazzulino

  For documentation purposes, I just draw the following UML sequence diagrams for the “Astoria” pipeline, using Visual Studio 2010 Ultimate: For a single-entity (or non-batched) request, this is the sequence: For a batch request, this is the sequence instead: DataService component is your own DataService<T>-derived class, and DataService.ProcessingPipeline refers to its ProcessingPipeline property pipeline events.   /kzu

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• Visual NHibernate Update

  - by Ricardo Peres

  I have previously talked about Visual NHibernate. It has grown since last time, now offering support for multiple databases (SQL Server, Oracle, MySQL, PostgreSQL, Firebird), generates projects from existing databases or from existing Visual Studio projects and produces XML or Fluent mappings, to name just a few. To me it is by far the most interesting tools for working with NHibernate I know of (granted, I haven't tried NHibernate Profiler). For a limited period, Slyce Software is offering a 30% discount, until the final version is released, so you may want to have a look. Please note that I am in no way related to Slyce, but made some feature requests which have been implemented (thanks, Gareth!).

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• Resolving harmless binding errors in WPF II : 2 approaches for removing data binding errors due to heterogeneous types in a hierarchical view

  - by akjoshi

  This is a continuation post to my previous post Resolving harmless binding errors in WPF in which I talked about various ways of  resolving different binding errors etc. I recently came across another situation in which we get these binding errors and how they can be resolved. Problem: If you have a tree with 2 types of items in it and you use different DataTypes for each of them, then you will get binding errors because of missing Properties in either one of the item. In our case we had binding...(read more)

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• Code and Slides: Getting Started Building Windows 8 HTML/JavaScript Metro Apps

  - by dwahlin

  This presentation is from a talk I gave at the spring 2012 DevConnections conference. It covers some of the key topics you need to know to get started building Windows 8 HTML/JavaScript Metro apps including navigation options, UI surfaces that can be used, controls, data binding and templates, and animations. View more of my presentations here. Sample code shown in the presentation can be found here. A large number of samples are available in the Windows 8 SDK which can be found here.

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• Using Sandcastle to build code contracts documentation

  - by DigiMortal

  In my last posting about code contracts I showed how code contracts are documented in XML-documents. In this posting I will show you how to get code contracts documented with Sandcastle and Sandcastle Help File Builder. Before we start, let’s download Sandcastle tools we need: Sandcastle Sandcastle Help File Builder Install Sandcastle first and then Sandcastle Help File Builder. Because we are generating only HTML based documentation we upload to server we don’t need any other tools. Of course, we need Cassini or IIS, but I expect it to be already there in your machine. Open your project and turn on XML-documentation for project and contracts. Now let’s run Sandcastle Help File Builder. We have to create new project and add our Visual Studio solution to this project. Now set the HelpFileFormat parameter value to be Website and let builder build the help. You have to wait about two or three minutes until help is ready. Take a look at your documentation that Sandcastle generated – you see not much information there about code contracts and their rules. Enabling code contracts documentation Now let’s include code contracts to documentation. Follow these steps: Open Sandcastle folder and make copy of vs2005 folder. Open CodeContracts folder (c:\program files\microsoft\contracts\) and unzip the archive from sandcastle folder. Copy all unzipped files to Sandcastle folder. Create (yes, create new) and build your Sandcastle Help File Builder documentation project again. Open help. In my case I see something like this now. As you can see then contracts are documented pretty well. We can easily turn on code contracts XML-documentation generation and all our contracts are documented automatically. To get documentation work we had to use Sandcastle help file fixes that are installed with code contracts and if we had previously Sandcastle Help File Builder project we had to create it from start to get new rules accepted. Once the documentation support for contracts works we have to do nothing more to get contracts documented.

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• Beware of const members

  - by nmarun

  I happened to learn a new thing about const today and how one needs to be careful with its usage. Let’s say I have a third-party assembly ‘ConstVsReadonlyLib’ with a class named ConstSideEffect.cs: 1: public class ConstSideEffect 2: { 3: public static readonly int StartValue = 10; 4: public const int EndValue = 20; 5: } In my project, I reference the above assembly as follows: 1: static void Main(string[] args) 2: { 3: for (int i = ConstSideEffect.StartValue; i < ConstSideEffect.EndValue; i++) 4: { 5: Console.WriteLine(i); 6: } 7: Console.ReadLine(); 8: } You’ll see values 10 through 19 as expected. Now, let’s say I receive a new version of the ConstVsReadonlyLib. 1: public class ConstSideEffect 2: { 3: public static readonly int StartValue = 5; 4: public const int EndValue = 30; 5: } If I just drop this new assembly in the bin folder and run the application, without rebuilding my console application, my thinking was that the output would be from 5 to 29. Of course I was wrong… if not you’d not be reading this blog. The actual output is from 5 through 19. The reason is due to the behavior of const and readonly members. To begin with, const is the compile-time constant and readonly is a runtime constant. Next, when you compile the code, a compile-time constant member is replaced with the value of the constant in the code. But, the IL generated when you reference a read-only constant, references the readonly variable, not its value. So, the IL version of the Main method, after compilation actually looks something like: 1: static void Main(string[] args) 2: { 3: for (int i = ConstSideEffect.StartValue; i < 20; i++) 4: { 5: Console.WriteLine(i); 6: } 7: Console.ReadLine(); 8: } I’m no expert with this IL thingi, but when I look at the disassembled code of the exe file (using IL Disassembler), I see the following: I see our readonly member still being referenced by the variable name (ConstVsReadonlyLib.ConstSideEffect::StartValue) in line 0001. Then there’s the Console.WriteLine in line 000b and finally, see the value of 20 in line 0017. This, I’m pretty sure is our const member being replaced by its value which marks the upper bound of the ‘for’ loop. Now you know why the output was from 5 through 19. This definitely is a side-effect of having const members and one needs to be aware of it. While we’re here, I’d like to add a few other points about const and readonly members: const is slightly faster, but is less flexible readonly cannot be declared within a method scope const can be used only on primitive types (numbers and strings) Just wanted to share this before going to bed!

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• Using runtime checking of code contracts in Visual Studio 2010

  - by DigiMortal

  In my last posting about code contracts I introduced how to check input parameters of randomizer using static contracts checking. But you can also compile code contracts to your assemblies and use them also in runtime. In this posting I will show you simple example about runtime checking of code contracts. NB! If you want to play with code and try out things described here feel free to download example solution. if you are speaker and want to use this solution as a part of your sessions then feel free to do so, but don’t forget to refer me and this blog as source of this solution. And please let me know about your session. As a speaker I am very interested about it. :) To see how code contracts are checked at runtime we have to enable runtime checking from project properties. Make sure you have checked the box “Perform Runtime Contract Checking” and make sure you select “Full” from dropdown. These parts are in red box on the screenshot below. Visual Studio 2010 settings for code contracts. Runtime Checking is turned on and checks are made only in public surface. Click on image to see it at original size.  Save project settings. Then compile code and run it. As soon as code execution hits the call to GetRandomFromRangeContracted() exception is thrown. If you are not currently playing with solution referred above take a look at the following screenshot. Visual Studio 2010 runtime checking of code contracts. Exception of type ContractException is thrown when contract is violated. Click on image to see it at original size.  The exact type of exception is ContractException and it is defined in System.Diagnostics.Contracts.__ContractsRuntime namespace. In our example the message of exception is following: "Precondition failed: min < max  Min must be less than max" Besides the description we inserted for the case contract violation the message also contains violated contract type. In this case the type of contract is Precondition. Conclusion Using runtime checking of code contracts enables you to take code contracts with your code and have them checked every time when your methods are called. This way you can assure that all conditions are met to run method or exception is thrown and calling system has to handle the situation.

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• [Silverlight] How to watermark a WriteableBitmap with a text

  - by Benjamin Roux

  Hello, In my current project, I needed to watermark a WriteableBitmap with a text. As I couldn’t find anything I decided to create a small extension method to do so. public static class WriteableBitmapEx { /// <summary> /// Creates a watermark on the specified image /// </summary> /// <param name="input">The image to create the watermark from</param> /// <param name="watermark">The text to watermark</param> /// <param name="color">The color - default is White</param> /// <param name="fontSize">The font size - default is 50</param> /// <param name="opacity">The opacity - default is 0.25</param> /// <param name="hasDropShadow">Specifies if a drop shadow effect must be added - default is true</param> /// <returns>The watermarked image</returns> public static WriteableBitmap Watermark(this WriteableBitmap input, string watermark, Color color = default(Color), double fontSize = 50, double opacity = 0.25, bool hasDropShadow = true) { var watermarked = GetTextBitmap(watermark, fontSize, color == default(Color) ? Colors.White : color, opacity, hasDropShadow); var width = watermarked.PixelWidth; var height = watermarked.PixelHeight; var result = input.Clone(); var position = new Rect(input.PixelWidth - width - 20 /* right margin */, input.PixelHeight - height, width, height); result.Blit(position, watermarked, new Rect(0, 0, width, height)); return result; } /// <summary> /// Creates a WriteableBitmap from a text /// </summary> /// <param name="text"></param> /// <param name="fontSize"></param> /// <param name="color"></param> /// <param name="opacity"></param> /// <param name="hasDropShadow"></param> /// <returns></returns> private static WriteableBitmap GetTextBitmap(string text, double fontSize, Color color, double opacity, bool hasDropShadow) { TextBlock txt = new TextBlock(); txt.Text = text; txt.FontSize = fontSize; txt.Foreground = new SolidColorBrush(color); txt.Opacity = opacity; if (hasDropShadow) txt.Effect = new DropShadowEffect(); WriteableBitmap bitmap = new WriteableBitmap((int)txt.ActualWidth, (int)txt.ActualHeight); bitmap.Render(txt, null); bitmap.Invalidate(); return bitmap; } } For this code to run, you need the WritableBitmapEx library. As you can see, it’s quite simple. You just need to call the Watermark method and pass it the text you want to add in your image. You can also pass optional parameters like the color, the opacity, the fontsize or if you want a drop shadow effect. I could have specify other parameters like the position or the the font family but you can change the code if you need to. Here’s what it can give Hope this helps.

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• How can I boost my C# learning curve?

  - by MSU

  I have been learning programming, mostly C# and .net stuff. And I have target to become a fulltime .NET developer. But I am feeling that learning Graph is very slow, I have been learning C# programming, doing some coding everyday, but how I can learn very fast and increase my skills rapidly? I know there should be a balance of coding and reading, as without reading I can't code and without coding I can't increase my skills. SO, I am requesting here suggesting from experts on how I bring more pace to my learning curve? I intend to give 4-6 hours daily for this and on weekends 10+ hours.

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• Sort method versus OrderBy LINQ extension method

  - by nmarun

  I have a class Product with an Id and a Name as properties. There are multiple ways of getting a list of products to display in sorted/ordered fashion, say, by the Name of the product. The two I’m concerned about here are the Sort and the OrderBy extension method through LINQ and the difference between them. 1: public class Product 2: { 3: public int Id { get; set; } 4: public string Name { get; set; } 5: } Below is the list of products that I’ll be using and is defined somewhere in the Program.cs...(read more)

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• Action delegate in C#

  - by Jalpesh P. Vadgama

  In last few posts about I have written lots of things about delegates and this post is also part of that series. In this post we are going to learn about Action delegates in C#.  Following is a list of post related to delegates. Delegates in C#. Multicast Delegates in C#. Func Delegates in C#. Action Delegates in c#: As per MSDN action delegates used to pass a method as parameter without explicitly declaring custom delegates. Action Delegates are used to encapsulate method that does not have return value. C# 4.0 Action delegates have following different variants like following. It can take up to 16 parameters. Action – It will be no parameter and does not return any value. Action(T) Action(T1,T2) Action(T1,T2,T3) Action(T1,T2,T3,T4) Action(T1,T2,T3,T4,T5) Action(T1,T2,T3,T4,T5,T6) Action(T1,T2,T3,T4,T5,T6,T7) Action(T1,T2,T3,T4,T5,T6,T7,T8) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9,T10) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15) Action(T1,T2,T3,T4,T5,T6,T7,T8,T9,T10,T11,T12,T13,T14,T15,T16) So for this Action delegate you can have up to 16 parameters for Action.  Sound interesting!!… Enough theory now. It’s time to implement real code. Following is a code for that. using System; using System.Collections.Generic; namespace DelegateExample { class Program { static void Main(string[] args) { Action<String> Print = p => Console.WriteLine(p); Action<String,String> PrintAnother = (p1,p2)=> Console.WriteLine(string.Format("{0} {1}",p1,p2)); Print("Hello"); PrintAnother("Hello","World"); } } } In the above code you can see that I have created two Action delegate Print and PrintAnother. Print have one string parameter and its printing that. While PrintAnother have two string parameter and printing both the strings via Console.Writeline. Now it’s time to run example and following is the output as expected. That’s it. Hope you liked it. Stay tuned for more updates!!

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• Example: Controlling randomizer using code contracts

  - by DigiMortal

  One cool addition to Visual Studio 2010 is support for code contracts. Code contracts make sure that all conditions under what method is supposed to run correctly are met. Those who are familiar with unit tests will find code contracts easy to use. In this posting I will show you simple example about static contract checking (example solution is included). To try out code contracts you need at least Visual Studio 2010 Standard Edition. Also you need code contracts package. You can download package from DevLabs Code Contracts page. NB! Speakers, you can use the example solution in your presentations as long as you mention me and this blog in your sessions. Solution has readme.txt file that gives you steps to go through when presenting solution in sessions. This blog posting is companion posting for Visual Studio solution referred below. As an example let’s look at the following class. public class Randomizer {     public static int GetRandomFromRange(int min, int max)     {         var rnd = new Random();         return rnd.Next(min, max);     }       public static int GetRandomFromRangeContracted(int min, int max)     {         Contract.Requires(min < max, "Min must be less than max");           var rnd = new Random();         return rnd.Next(min, max);     } } GetRandomFromRange() method returns results without any checking. GetRandomFromRangeContracted() uses one code contract that makes sure that minimum value is less than maximum value. Now let’s run the following code. class Program {     static void Main(string[] args)     {         var random1 = Randomizer.GetRandomFromRange(0, 9);         Console.WriteLine("Random 1: " + random1);           var random2 = Randomizer.GetRandomFromRange(1, 1);         Console.WriteLine("Random 2: " + random2);           var random3 = Randomizer.GetRandomFromRangeContracted(5, 5);         Console.WriteLine("Random 3: " + random3);           Console.WriteLine(" ");         Console.WriteLine("Press any key to exit ...");         Console.ReadKey();     } } As we have not turned on support for code contracts the code runs without any problems and we get no warnings by Visual Studio that something is wrong. Now let’s turn on static checking for code contracts. As you can see then code still compiles without any errors but Visual Studio warns you about possible problems with contracts. Click on image to see it at original size.  When we open Error list and run our application we get the following output to errors list. Note that these messages are not shown immediately. There is little delay between application starting and appearance of these messages. So wait couple of seconds before going out of your mind. Click on image to see it at original size.  If you look at these warnings you can see that warnings show you illegal calls and also contracts against what they are going. Third warning points to GetRandomFromRange() method and shows that there should be also problem that can be detected by contract. Download Code Contracts example VS2010 solution | 30KB

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• Back from the OData Roadshow

  - by Fabrice Marguerie

  I'm just back from the OData Roadshow with Douglas Purdy and Jonathan Carter. Paris was the last location of seven cities around the world.If there was something you wanted to know about OData, that was the place to be!These guys gave a great tour around OData. I learned things I didn't know about OData and I was able to give a demo of Sesame to the audience.More ideas and use cases popping-up!

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• Getting Current Native Thread

  - by Ricardo Peres

  The native OS threads running in the current process are exposed through the Threads property of the Process class. Please note that this is not the same as a managed thread, these are the actual native threads running on the operating system. In order to get a pointer to the current executing thread, we must use P/Invoke. Here's how we do it: [DllImport("kernel32.dll")] public static extern UInt32 GetCurrentThreadId(); UInt32 id = GetCurrentThreadId(); ProcessThread thread = Process.GetCurrentProcess().Threads.Cast().Where(t = t.Id == id).Single(); SyntaxHighlighter.config.clipboardSwf = 'http://alexgorbatchev.com/pub/sh/2.0.320/scripts/clipboard.swf'; SyntaxHighlighter.brushes.CSharp.aliases = ['c#', 'c-sharp', 'csharp']; SyntaxHighlighter.all();

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• First class language in Visual Studio 2010 using F#

  - by Aamir Hasan

   F# is a strongly-typed language like C#.It is light weight syntax just like Python.It give you math-like feel. let data = (1,2,3)   let rotations (x, y, z) =     [ (x, y, z);       (z, x, y);       (y, z, x) ]   let derivative f x =     let p1 = f (x - 0.05)     let p2 = f (x + 0.05)     (p2 - p1) / 0.1   let f x = 2.0*x*x - 6.0*x + 3.0   let df = derivative f   System.Console.WriteLine("The derivative of f at x=4 is {0}", df 4.0)   This program will print: “The derivative of f at x=4 is 10”That’s a quick look at just a few of the exciting features of F#.  For more on F#, visit the F# Development Center on MSDN.  

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• A WPF Image/Text Button

  - by psheriff

  Some of our customers are asking us to give them a Windows 8 look and feel for their applications. This includes things like buttons, tiles, application bars, and other features. In this blog post I will describe how to create a button that looks similar to those you will find in a Windows 8 application bar. In Figure 1 you can see two different kinds of buttons. In the top row is a WPF button where the content of the button includes a Border, an Image and a TextBlock. In the bottom row are four...(read more)

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• [Windows 8] Please implement the PlayTo feature in your media apps

  - by Benjamin Roux

  One of the greatest feature in Windows 8 apps is the ability to stream the video/photos/music you’re playing to any DLNA capable device in your network. Meaning that if you’re watching a movie on Netflix on your brand new Surface tablet in your garden, you can continue to watch it without interruption on your TV if you decide to go back inside ! Isn’t that awesome? The best thing is that it takes very few lines to implement that in an app and it’s very easy. You just have to subscribe to one event and feed the EventArgs with the stream you want to display. You can either stream a video/music from a MediaElement/MediaPlayer (see PlayerFramework on CodePlex) or from a simple Image control. Code’s better than text so I invite you to go the sample code of the PlayTo feature on the msdn (it features code for JS, C# and C++). So if you’re developing an app capable of playing video, music or just display some photos, please implement the PlayTo, it will bring a plus to your app.

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• LINQ: Enhancing Distinct With The SelectorEqualityComparer

  - by Paulo Morgado

  On my last post, I introduced the PredicateEqualityComparer and a Distinct extension method that receives a predicate to internally create a PredicateEqualityComparer to filter elements. Using the predicate, greatly improves readability, conciseness and expressiveness of the queries, but it can be even better. Most of the times, we don’t want to provide a comparison method but just to extract the comaprison key for the elements. So, I developed a SelectorEqualityComparer that takes a method that extracts the key value for each element. Something like this: public class SelectorEqualityComparer<TSource, Tkey> : EqualityComparer<TSource> where Tkey : IEquatable<Tkey> { private Func<TSource, Tkey> selector; public SelectorEqualityComparer(Func<TSource, Tkey> selector) : base() { this.selector = selector; } public override bool Equals(TSource x, TSource y) { Tkey xKey = this.GetKey(x); Tkey yKey = this.GetKey(y); if (xKey != null) { return ((yKey != null) && xKey.Equals(yKey)); } return (yKey == null); } public override int GetHashCode(TSource obj) { Tkey key = this.GetKey(obj); return (key == null) ? 0 : key.GetHashCode(); } public override bool Equals(object obj) { SelectorEqualityComparer<TSource, Tkey> comparer = obj as SelectorEqualityComparer<TSource, Tkey>; return (comparer != null); } public override int GetHashCode() { return base.GetType().Name.GetHashCode(); } private Tkey GetKey(TSource obj) { return (obj == null) ? (Tkey)(object)null : this.selector(obj); } } Now I can write code like this: .Distinct(new SelectorEqualityComparer<Source, Key>(x => x.Field)) And, for improved readability, conciseness and expressiveness and support for anonymous types the corresponding Distinct extension method: public static IEnumerable<TSource> Distinct<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> selector) where TKey : IEquatable<TKey> { return source.Distinct(new SelectorEqualityComparer<TSource, TKey>(selector)); } And the query is now written like this: .Distinct(x => x.Field) For most usages, it’s simpler than using a predicate.

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• How to mock a dynamic object

  - by Daniel Cazzulino

  Someone asked me how to mock a dynamic object with Moq, which might be non-obvious. Given the following interface definition: public interface IProject { string Name { get; } dynamic Data { get; } } When you try to setup the mock for the dynamic property values, you get:   What’s important to realize is that a dynamic object is just a plain object, whose properties happen to be resolved at runtime. Kinda like reflection, if you will: all public properties of whatever object happens to be the instance, will be resolved just fine at runtime. Therefore, one way to mock this dynamic is to just create an anonymous type with the properties we want, and set the dynamic property to return that:...Read full article

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• Silverlight 4 Tools + WCF RIA Services Released

  - by guybarrette

  Microsoft has released the final versions of the Silverlight 4 Tools along with WCF RIA Services and the Silverlight Toolkit. Check Tim Heuer’s blog for all the info. var addthis_pub="guybarrette";

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• Detecting HTML5/CSS3 Features using Modernizr

  - by dwahlin

  HTML5, CSS3, and related technologies such as canvas and web sockets bring a lot of useful new features to the table that can take Web applications to the next level. These new technologies allow applications to be built using only HTML, CSS, and JavaScript allowing them to be viewed on a variety of form factors including tablets and phones. Although HTML5 features offer a lot of promise, it’s not realistic to develop applications using the latest technologies without worrying about supporting older browsers in the process. If history has taught us anything it’s that old browsers stick around for years and years which means developers have to deal with backward compatibility issues. This is especially true when deploying applications to the Internet that target the general public. This begs the question, “How do you move forward with HTML5 and CSS3 technologies while gracefully handling unsupported features in older browsers?” Although you can write code by hand to detect different HTML5 and CSS3 features, it’s not always straightforward. For example, to check for canvas support you need to write code similar to the following:   <script> window.onload = function () { if (canvasSupported()) { alert('canvas supported'); } }; function canvasSupported() { var canvas = document.createElement('canvas'); return (canvas.getContext && canvas.getContext('2d')); } </script> If you want to check for local storage support the following check can be made. It’s more involved than it should be due to a bug in older versions of Firefox. <script> window.onload = function () { if (localStorageSupported()) { alert('local storage supported'); } }; function localStorageSupported() { try { return ('localStorage' in window && window['localStorage'] != null); } catch(e) {} return false; } </script> Looking through the previous examples you can see that there’s more than meets the eye when it comes to checking browsers for HTML5 and CSS3 features. It takes a lot of work to test every possible scenario and every version of a given browser. Fortunately, you don’t have to resort to writing custom code to test what HTML5/CSS3 features a given browser supports. By using a script library called Modernizr you can add checks for different HTML5/CSS3 features into your pages with a minimal amount of code on your part. Let’s take a look at some of the key features Modernizr offers.   Getting Started with Modernizr The first time I heard the name “Modernizr” I thought it “modernized” older browsers by added missing functionality. In reality, Modernizr doesn’t actually handle adding missing features or “modernizing” older browsers. The Modernizr website states, “The name Modernizr actually stems from the goal of modernizing our development practices (and ourselves)”. Because it relies on feature detection rather than browser sniffing (a common technique used in the past – that never worked that great), Modernizr definitely provides a more modern way to test features that a browser supports and can even handle loading additional scripts called shims or polyfills that fill in holes that older browsers may have. It’s a great tool to have in your arsenal if you’re a web developer. Modernizr is available at http://modernizr.com. Two different types of scripts are available including a development script and custom production script. To generate a production script, the site provides a custom script generation tool rather than providing a single script that has everything under the sun for HTML5/CSS3 feature detection. Using the script generation tool you can pick the specific test functionality that you need and ignore everything that you don’t need. That way the script is kept as small as possible. An example of the custom script download screen is shown next. Notice that specific CSS3, HTML5, and related feature tests can be selected. Once you’ve downloaded your custom script you can add it into your web page using the standard <script> element and you’re ready to start using Modernizr. <script src="Scripts/Modernizr.js" type="text/javascript"></script>   Modernizr and the HTML Element Once you’ve add a script reference to Modernizr in a page it’ll go to work for you immediately. In fact, by adding the script several different CSS classes will be added to the page’s <html> element at runtime. These classes define what features the browser supports and what features it doesn’t support. Features that aren’t supported get a class name of “no-FeatureName”, for example “no-flexbox”. Features that are supported get a CSS class name based on the feature such as “canvas” or “websockets”. An example of classes added when running a page in Chrome is shown next:   <html class=" js flexbox canvas canvastext webgl no-touch geolocation postmessage websqldatabase indexeddb hashchange history draganddrop websockets rgba hsla multiplebgs backgroundsize borderimage borderradius boxshadow textshadow opacity cssanimations csscolumns cssgradients cssreflections csstransforms csstransforms3d csstransitions fontface generatedcontent video audio localstorage sessionstorage webworkers applicationcache svg inlinesvg smil svgclippaths"> Here’s an example of what the <html> element looks like at runtime with Internet Explorer 9:   <html class=" js no-flexbox canvas canvastext no-webgl no-touch geolocation postmessage no-websqldatabase no-indexeddb hashchange no-history draganddrop no-websockets rgba hsla multiplebgs backgroundsize no-borderimage borderradius boxshadow no-textshadow opacity no-cssanimations no-csscolumns no-cssgradients no-cssreflections csstransforms no-csstransforms3d no-csstransitions fontface generatedcontent video audio localstorage sessionstorage no-webworkers no-applicationcache svg inlinesvg smil svgclippaths">   When using Modernizr it’s a common practice to define an <html> element in your page with a no-js class added as shown next:   <html class="no-js">   You’ll see starter projects such as HTML5 Boilerplate (http://html5boilerplate.com) or Initializr (http://initializr.com) follow this approach (see my previous post for more information on HTML5 Boilerplate). By adding the no-js class it’s easy to tell if a browser has JavaScript enabled or not. If JavaScript is disabled then no-js will stay on the <html> element. If JavaScript is enabled, no-js will be removed by Modernizr and a js class will be added along with other classes that define supported/unsupported features. Working with HTML5 and CSS3 Features You can use the CSS classes added to the <html> element directly in your CSS files to determine what style properties to use based upon the features supported by a given browser. For example, the following CSS can be used to render a box shadow for browsers that support that feature and a simple border for browsers that don’t support the feature: .boxshadow #MyContainer { border: none; -webkit-box-shadow: #666 1px 1px 1px; -moz-box-shadow: #666 1px 1px 1px; } .no-boxshadow #MyContainer { border: 2px solid black; }   If a browser supports box-shadows the boxshadow CSS class will be added to the <html> element by Modernizr. It can then be associated with a given element. This example associates the boxshadow class with a div with an id of MyContainer. If the browser doesn’t support box shadows then the no-boxshadow class will be added to the <html> element and it can be used to render a standard border around the div. This provides a great way to leverage new CSS3 features in supported browsers while providing a graceful fallback for older browsers. In addition to using the CSS classes that Modernizr provides on the <html> element, you also use a global Modernizr object that’s created. This object exposes different properties that can be used to detect the availability of specific HTML5 or CSS3 features. For example, the following code can be used to detect canvas and local storage support. You can see that the code is much simpler than the code shown at the beginning of this post. It also has the added benefit of being tested by a large community of web developers around the world running a variety of browsers.   $(document).ready(function () { if (Modernizr.canvas) { //Add canvas code } if (Modernizr.localstorage) { //Add local storage code } }); The global Modernizr object can also be used to test for the presence of CSS3 features. The following code shows how to test support for border-radius and CSS transforms:   $(document).ready(function () { if (Modernizr.borderradius) { $('#MyDiv').addClass('borderRadiusStyle'); } if (Modernizr.csstransforms) { $('#MyDiv').addClass('transformsStyle'); } });   Several other CSS3 feature tests can be performed such as support for opacity, rgba, text-shadow, CSS animations, CSS transitions, multiple backgrounds, and more. A complete list of supported HTML5 and CSS3 tests that Modernizr supports can be found at http://www.modernizr.com/docs.   Loading Scripts using Modernizr In cases where a browser doesn’t support a specific feature you can either provide a graceful fallback or load a shim/polyfill script to fill in missing functionality where appropriate (more information about shims/polyfills can be found at https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills). Modernizr has a built-in script loader that can be used to test for a feature and then load a script if the feature isn’t available. The script loader is built-into Modernizr and is also available as a standalone yepnope script (http://yepnopejs.com). It’s extremely easy to get started using the script loader and it can really simplify the process of loading scripts based on the availability of a particular browser feature. To load scripts dynamically you can use Modernizr’s load() function which accepts properties defining the feature to test (test property), the script to load if the test succeeds (yep property), the script to load if the test fails (nope property), and a script to load regardless of if the test succeeds or fails (both property). An example of using load() with these properties is show next: Modernizr.load({ test: Modernizr.canvas, yep: 'html5CanvasAvailable.js’, nope: 'excanvas.js’, both: 'myCustomScript.js' }); In this example Modernizr is used to not only load scripts but also to test for the presence of the canvas feature. If the target browser supports the HTML5 canvas then the html5CanvasAvailable.js script will be loaded along with the myCustomScript.js script (use of the yep property in this example is a bit contrived – it was added simply to demonstrate how the property can be used in the load() function). Otherwise, a polyfill script named excanvas.js will be loaded to add missing canvas functionality for Internet Explorer versions prior to 9. Once excanvas.js is loaded the myCustomScript.js script will be loaded. Because Modernizr handles loading scripts, you can also use it in creative ways. For example, you can use it to load local scripts when a 3rd party Content Delivery Network (CDN) such as one provided by Google or Microsoft is unavailable for whatever reason. The Modernizr documentation provides the following example that demonstrates the process for providing a local fallback for jQuery when a CDN is down:   Modernizr.load([ { load: '//ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.js', complete: function () { if (!window.jQuery) { Modernizr.load('js/libs/jquery-1.6.4.min.js'); } } }, { // This will wait for the fallback to load and // execute if it needs to. load: 'needs-jQuery.js' } ]); This code attempts to load jQuery from the Google CDN first. Once the script is downloaded (or if it fails) the function associated with complete will be called. The function checks to make sure that the jQuery object is available and if it’s not Modernizr is used to load a local jQuery script. After all of that occurs a script named needs-jQuery.js will be loaded. Conclusion If you’re building applications that use some of the latest and greatest features available in HTML5 and CSS3 then Modernizr is an essential tool. By using it you can reduce the amount of custom code required to test for browser features and provide graceful fallbacks or even load shim/polyfill scripts for older browsers to help fill in missing functionality. 

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• Stardock Fences

  - by guybarrette

  I installed the free Fences utility program by Stardock today.  What a cool way to group and organize your desktop icons. Here’s my desktop with a bunch of icons grouped in fences. var addthis_pub="guybarrette";

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