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  • How to access a named element of a derived user control in silverlight ?

    - by Mrt
    Hello, I have a custom base user control in silverlight. <UserControl x:Class="Problemo.MyBaseControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="400"> <Grid x:Name="LayoutRoot" Background="White"> <Border Name="HeaderControl" Background="Red" /> </Grid> </UserControl> With the following code behind public partial class MyBaseControl : UserControl { public UIElement Header { get; set; } public MyBaseControl() { InitializeComponent(); Loaded += MyBaseControl_Loaded; } void MyBaseControl_Loaded(object sender, RoutedEventArgs e) { HeaderControl.Child = Header; } } I have a derived control. <me:MyBaseControl x:Class="Problemo.MyControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" xmlns:me="clr-namespace:Problemo" d:DesignHeight="300" d:DesignWidth="400"> <me:MyBaseControl.Header> <TextBlock Name="header" Text="{Binding Text}" /> </me:MyBaseControl.Header> </me:MyBaseControl> With the following code behind. public partial class MyControl : MyBaseControl { public string Text { get; set; } public MyControl(string text) { InitializeComponent(); Text = text; } } I'm trying to set the text value of the header textblock in the derived control. It would be nice to be able to set both ways, i.e. with databinding or in the derived control code behind, but neither work. With the data binding, it doesn't work. If I try in the code behind I get a null reference to 'header'. This is silverlight 4 (not sure if that makes a difference) Any suggestions on how to do with with both databinding and in code ? Cheers

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  • vim plugin to show current Perl subroutine

    - by Andrew
    I'm trying to make a vim plugin that will split the window on load and simulate a info bar at the top of my terminal. I've got it sorta working but I think I've either reached limits of my knowledge of vim syntax or there's a logic problem in my code. The desired effect would be to do a reverse search for any declaration of a Perl subroutine form my current location in the active buffer and display the line in the top buffer. I'm also trying to make it skip that buffer when I switch buffers with <C-R>. My attempt at that so far can be seen in the mess of nested if statements. Anyway, here's the code. I would greatly appreciate feedback from anyone. (pastebin pastebin.com/8cuMPn1Q) let s:current_function_bufname = 'Current\ Function\/Subroutine' function! s:get_current_function_name(no_echo) let lnum = line(".") let col = col(".") if a:no_echo let s:current_function_name = getline(search("^[^s]sub .$", 'bW')) else echohl ModeMsg echo getline(search("^[^s]sub .$", 'bW')) "echo getline(search("^[^ \t#/]\{2}.[^:]\s$", 'bW')) echohl None endif endfunction let s:previous_winbufnr = 1 let s:current_function_name = '' let s:current_function_buffer_created = 0 let s:current_function_bufnr = 2 function! s:show_current_function() let total_buffers = winnr('$') let current_winbufnr = winnr() if s:previous_winbufnr != current_winbufnr if bufname(current_winbufnr) == s:current_function_bufname if s:previous_winbufnr < current_winbufnr let i = current_winbufnr + 1 if i total_buffers let i = 1 endif if i == s:current_function_bufnr let i = i + 1 endif if i total buffers let i = 1 endif exec i.'wincmd w' else let i = current_winbufnr - 1 if i < 1 let i = total_buffers endif if i == s:current_function_bufnr let i = i - 1 endif if i < 1 let i = total_buffers endif try exec i.'wincmd w' finally exec total_buffers.'wincmd w' endtry endif endif let s:previous_winbufnr = current_winbufnr return 1 endif if s:current_function_buffer_created == 0 exec 'top 1 split '.s:current_function_bufname call s:set_as_scratch_buffer() let s:current_function_buffer_created = 1 let s:current_function_bufnr = winnr() endif call s:activate_buffer_by_name(s:current_function_bufname) setlocal modifiable call s:get_current_function_name(1) call setline(1, s:current_function_name) setlocal nomodifiable call s:activate_buffer_by_name(bufname(current_winbufnr)) endfunction function! s:set_as_scratch_buffer() setlocal noswapfile setlocal nomodifiable setlocal bufhidden=delete setlocal buftype=nofile setlocal nobuflisted setlocal nonumber setlocal nowrap setlocal cursorline endfunction function! s:activate_buffer_by_name(name) for i in range(1, winnr('$')) let name = bufname(winbufnr(i)) let full_name = fnamemodify(bufname(winbufnr(i)), ':p') if name == a:name || full_name == a:name exec i.'wincmd w' return 1 endif endfor return 0 endfunction set laststatus=2 autocmd! CursorMoved,CursorMovedI,BufWinEnter * call s:show_current_function() (pastebin pastebin.com/8cuMPn1Q) similar to VIM: display custom reference bar on top of window and http://vim.wikia.com/wiki/Show_current_function_name_in_C_programs

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  • Rails 3 NameError (cannot remove Object::Version) error

    - by Jeff D
    Can anyone point me at what might be causing this error? There is no ApplicationTrace, and it locks the server hard on my development machine. I think it has something to do with the way rails reloads your classes in development mode, and it appears to have something to do with a Version constant. I can't find a reference to this though. Can anyone point me in the direction of what would cause this? activesupport (3.0.3) lib/active_support/dependencies.rb:645:in `remove_const' activesupport (3.0.3) lib/active_support/dependencies.rb:645:in `remove_constant' activesupport (3.0.3) lib/active_support/dependencies.rb:645:in `instance_eval' activesupport (3.0.3) lib/active_support/dependencies.rb:645:in `remove_constant' activesupport (3.0.3) lib/active_support/dependencies.rb:521:in `remove_unloadable_constants!' activesupport (3.0.3) lib/active_support/dependencies.rb:521:in `each' activesupport (3.0.3) lib/active_support/dependencies.rb:521:in `remove_unloadable_constants!' activesupport (3.0.3) lib/active_support/dependencies.rb:317:in `clear' railties (3.0.3) lib/rails/application/bootstrap.rb:60:in `_callback_after_7' activesupport (3.0.3) lib/active_support/callbacks.rb:419:in `_run_call_callbacks' actionpack (3.0.3) lib/action_dispatch/middleware/callbacks.rb:44:in `call' rack (1.2.1) lib/rack/sendfile.rb:107:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/remote_ip.rb:48:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/show_exceptions.rb:46:in `call' railties (3.0.3) lib/rails/rack/logger.rb:13:in `call' rack (1.2.1) lib/rack/runtime.rb:17:in `call' activesupport (3.0.3) lib/active_support/cache/strategy/local_cache.rb:72:in `call' rack (1.2.1) lib/rack/lock.rb:11:in `call' rack (1.2.1) lib/rack/lock.rb:11:in `synchronize' rack (1.2.1) lib/rack/lock.rb:11:in `call' actionpack (3.0.3) lib/action_dispatch/middleware/static.rb:30:in `call' railties (3.0.3) lib/rails/application.rb:168:in `call' railties (3.0.3) lib/rails/application.rb:77:in `send' railties (3.0.3) lib/rails/application.rb:77:in `method_missing' railties (3.0.3) lib/rails/rack/log_tailer.rb:14:in `call' rack (1.2.1) lib/rack/content_length.rb:13:in `call' rack (1.2.1) lib/rack/handler/webrick.rb:52:in `service' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/httpserver.rb:104:in `service' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/httpserver.rb:65:in `run' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:173:in `start_thread' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:162:in `start' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:162:in `start_thread' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:95:in `start' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:92:in `each' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:92:in `start' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:23:in `start' /Volumes/files/jeffdeville/.rvm/rubies/ree-1.8.7-2010.02/lib/ruby/1.8/webrick/server.rb:82:in `start' rack (1.2.1) lib/rack/handler/webrick.rb:13:in `run' rack (1.2.1) lib/rack/server.rb:213:in `start' railties (3.0.3) lib/rails/commands/server.rb:65:in `start' railties (3.0.3) lib/rails/commands.rb:30 railties (3.0.3) lib/rails/commands.rb:27:in `tap' railties (3.0.3) lib/rails/commands.rb:27 script/rails:6:in `require' script/rails:6

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  • Why is my namespace not recognized in Visual Studio / xaml

    - by msfanboy
    Hello, these are my 2 classes a Attachable Property SelectedItems: code is from here: http://stackoverflow.com/questions/1297643/sync-selecteditems-in-a-muliselect-listbox-with-a-collection-in-viewmodel The namespace TBM.Helper is for sure proper as it works for other classes too. The namespace reference is also in the xaml file: xmlns:Helper="clr_namespace:TBM.Helper" But <ListBox Helper:SelectedItems.Items="{Binding SelectedItems}" ... does not work because = The property 'SelectedItems.Items' does not exist in XML namespace 'clr_namespace:TBM.Helper'. The attachable property 'Items' was not found in type 'SelectedItems What do I have to change ? using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows.Controls; using System.Collections; using System.Windows; namespace TBM.Helper { public static class SelectedItems : DependencyObject { private static readonly DependencyProperty SelectedItemsBehaviorProperty = DependencyProperty.RegisterAttached( "SelectedItemsBehavior", typeof(SelectedItemsBehavior), typeof(ListBox), null); public static readonly DependencyProperty ItemsProperty = DependencyProperty.RegisterAttached( "Items", typeof(IList), typeof(SelectedItems), new PropertyMetadata(null, ItemsPropertyChanged)); public static void SetItems(ListBox listBox, IList list) { listBox.SetValue(ItemsProperty, list); } public static IList GetItems(ListBox listBox) { return listBox.GetValue(ItemsProperty) as IList; } private static void ItemsPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) { var target = d as ListBox; if (target != null) { GetOrCreateBehavior(target, e.NewValue as IList); } } private static SelectedItemsBehavior GetOrCreateBehavior(ListBox target, IList list) { var behavior = target.GetValue(SelectedItemsBehaviorProperty) as SelectedItemsBehavior; if (behavior == null) { behavior = new SelectedItemsBehavior(target, list); target.SetValue(SelectedItemsBehaviorProperty, behavior); } return behavior; } } } using System.Windows; using System.Windows.Controls; using System.Collections; namespace TBM.Helper { public class SelectedItemsBehavior { private readonly ListBox _listBox; private readonly IList _boundList; public SelectedItemsBehavior(ListBox listBox, IList boundList) { _boundList = boundList; _listBox = listBox; SetSelectedItems(); _listBox.SelectionChanged += OnSelectionChanged; _listBox.DataContextChanged += OnDataContextChanged; } private void SetSelectedItems() { _listBox.SelectedItems.Clear(); foreach (object item in _boundList) { // References in _boundList might not be the same as in _listBox.Items int i = _listBox.Items.IndexOf(item); if (i >= 0) _listBox.SelectedItems.Add(_listBox.Items[i]); } } private void OnDataContextChanged(object sender, DependencyPropertyChangedEventArgs e) { SetSelectedItems(); } private void OnSelectionChanged(object sender, SelectionChangedEventArgs e) { _boundList.Clear(); foreach (var item in _listBox.SelectedItems) _boundList.Add(item); } } }

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  • A better UPDATE method in LINQ to SQL

    - by Refracted Paladin
    The below is a typical, for me, Update method in L2S. I am still fairly new to a lot of this(L2S & business app development) but this just FEELs wrong. Like there MUST be a smarter way of doing this. Unfortunately, I am having trouble visualizing it and am hoping someone can provide an example or point me in the right direction. To take a stab in the dark, would I have a Person Object that has all these fields as Properties? Then what, though? Is that redundant since L2S already mapped my Person Table to a Class? Is this just 'how it goes', that you eventually end up passing 30 parameters(or MORE) to an UPDATE statement at some point? For reference, this is a business app using C#, WinForms, .Net 3.5, and L2S over SQL 2005 Standard. Here is a typical Update Call for me. This is in a file(BLLConnect.cs) with other CRUD methods. Connect is the name of the DB that holds tblPerson When a user clicks save() this is what is eventually called with all of these fields having, potentially, been updated-- public static void UpdatePerson(int personID, string userID, string titleID, string firstName, string middleName, string lastName, string suffixID, string ssn, char gender, DateTime? birthDate, DateTime? deathDate, string driversLicenseNumber, string driversLicenseStateID, string primaryRaceID, string secondaryRaceID, bool hispanicOrigin, bool citizenFlag, bool veteranFlag, short ? residencyCountyID, short? responsibilityCountyID, string emailAddress, string maritalStatusID) { using (var context = ConnectDataContext.Create()) { var personToUpdate = (from person in context.tblPersons where person.PersonID == personID select person).Single(); personToUpdate.TitleID = titleID; personToUpdate.FirstName = firstName; personToUpdate.MiddleName = middleName; personToUpdate.LastName = lastName; personToUpdate.SuffixID = suffixID; personToUpdate.SSN = ssn; personToUpdate.Gender = gender; personToUpdate.BirthDate = birthDate; personToUpdate.DeathDate = deathDate; personToUpdate.DriversLicenseNumber = driversLicenseNumber; personToUpdate.DriversLicenseStateID = driversLicenseStateID; personToUpdate.PrimaryRaceID = primaryRaceID; personToUpdate.SecondaryRaceID = secondaryRaceID; personToUpdate.HispanicOriginFlag = hispanicOrigin; personToUpdate.CitizenFlag = citizenFlag; personToUpdate.VeteranFlag = veteranFlag; personToUpdate.ResidencyCountyID = residencyCountyID; personToUpdate.ResponsibilityCountyID = responsibilityCountyID; personToUpdate.EmailAddress = emailAddress; personToUpdate.MaritalStatusID = maritalStatusID; personToUpdate.UpdateUserID = userID; personToUpdate.UpdateDateTime = DateTime.Now; context.SubmitChanges(); } }

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  • Programmatically Binding to a Property

    - by M312V
    I know it's a generic title, but my question is specific. I think it will boil down to a question of practice. So, I have the following code: public class Component : UIElement { public Component() { this.InputBindings.Add(new MouseBinding(SomeCommandProperty, new MouseGesture(MouseAction.LeftClick))); } } I could easily aggregate the ViewModel that owns SomeCommandProperty into the Component class, but I'm currently waiving that option assuming there is another way. Component is a child of ComponentCollection which is child of a Grid which DataContext is the ViewModel. ComponentCollection as the name suggests contains a collection of Components. <Grid Name="myGrid"> <someNamespace:ComponentCollection x:Name="componentCollection"/> </Grid> It's the same scenario as the XAML below, but with TextBlock. I guess I'm trying to replicate what's being done in the XAML below programatically. Again, Component's top most ancestor's DataContext is set to ViewModel. <Grid Name="myGrid"> <TextBlock Text="SomeText"> <TextBlock.InputBindings> <MouseBinding Command="{Binding SomeCommandProperty}" MouseAction="LeftClick" /> </TextBlock.InputBindings> </TextBlock> </Grid> Update 1 Sorry, I'm unable to comment because I lack the reputation points. Basically, I have a custom control which inherit from a Panel which children are a collection of Component. It's not a hack, like I've mentioned, I could directly have access to SomeCommandProperty If I aggregate the ViewModel into Component. Doing so, however, feels icky. That is, having direct access to ViewModel from a Model. I guess the question I'm asking is. Given the situation that Component's parent UIElement's DataContext is set to ViewModel, is it possible to access SomeCommandProperty without Component owning a reference to the ViewModel that owns SomeCommandProperty? Programatically, that is. Using ItemsControl doesn't change the fact that I still need to bind SomeCommandProperty to each Items.

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  • How should I delete a child object from within a parent's slot? Possibly boost::asio specific.

    - by kaliatech
    I have written a network server class that maintains a std::set of network clients. The network clients emit a signal to the network server on disconnect (via boost::bind). When a network client disconnects, the client instance needs to be removed from the Set and eventually deleted. I would think this is a common pattern, but I am having problems that might, or might not, be specific to ASIO. I've tried to trim down to just the relevant code: /** NetworkServer.hpp **/ class NetworkServices : private boost::noncopyable { public: NetworkServices(void); ~NetworkServices(void); private: void run(); void onNetworkClientEvent(NetworkClientEvent&); private: std::set<boost::shared_ptr<const NetworkClient>> clients; }; /** NetworkClient.cpp **/ void NetworkServices::run() { running = true; boost::asio::io_service::work work(io_service); //keeps service running even if no operations // This creates just one thread for the boost::asio async network services boost::thread iot(boost::bind(&NetworkServices::run_io_service, this)); while (running) { boost::system::error_code err; try { tcp::socket* socket = new tcp::socket(io_service); acceptor->accept(*socket, err); if (!err) { NetworkClient* networkClient = new NetworkClient(io_service, boost::shared_ptr<tcp::socket>(socket)); networkClient->networkClientEventSignal.connect(boost::bind(&NetworkServices::onNetworkClientEvent, this, _1)); clients.insert(boost::shared_ptr<NetworkClient>(networkClient)); networkClient->init(); //kicks off 1st asynch_read call } } // etc... } } void NetworkServices::onNetworkClientEvent(NetworkClientEvent& evt) { switch(evt.getType()) { case NetworkClientEvent::CLIENT_ERROR : { boost::shared_ptr<const NetworkClient> clientPtr = evt.getClient().getSharedPtr(); // ------ THIS IS THE MAGIC LINE ----- // If I keep this, the io_service hangs. If I comment it out, // everything works fine (but I never delete the disconnected NetworkClient). // If actually deleted the client here I might expect problems because it is the caller // of this method via boost::signal and bind. However, The clientPtr is a shared ptr, and a // reference is being kept in the client itself while signaling, so // I would the object is not going to be deleted from the heap here. That seems to be the case. // Never-the-less, this line makes all the difference, most likely because it controls whether or not the NetworkClient ever gets deleted. clients.erase(clientPtr); //I should probably put this socket clean-up in NetworkClient destructor. Regardless by doing this, // I would expect the ASIO socket stuff to be adequately cleaned-up after this. tcp::socket& socket = clientPtr->getSocket(); try { socket.shutdown(boost::asio::socket_base::shutdown_both); socket.close(); } catch(...) { CommServerContext::error("Error while shutting down and closing socket."); } break; } default : { break; } } } /** NetworkClient.hpp **/ class NetworkClient : public boost::enable_shared_from_this<NetworkClient>, Client { NetworkClient(boost::asio::io_service& io_service, boost::shared_ptr<tcp::socket> socket); virtual ~NetworkClient(void); inline boost::shared_ptr<const NetworkClient> getSharedPtr() const { return shared_from_this(); }; boost::signal <void (NetworkClientEvent&)> networkClientEventSignal; void onAsyncReadHeader(const boost::system::error_code& error, size_t bytes_transferred); }; /** NetworkClient.cpp - onAsyncReadHeader method called from io_service.run() thread as result of an async_read operation. Error condition usually result of an unexpected client disconnect.**/ void NetworkClient::onAsyncReadHeader( const boost::system::error_code& error, size_t bytes_transferred) { if (error) { //Make sure this instance doesn't get deleted from parent/slot deferencing //Alternatively, somehow schedule for future delete? boost::shared_ptr<const NetworkClient> clientPtr = getSharedPtr(); //Signal to service that this client is disconnecting NetworkClientEvent evt(*this, NetworkClientEvent::CLIENT_ERROR); networkClientEventSignal(evt); networkClientEventSignal.disconnect_all_slots(); return; } I believe it's not safe to delete the client from within the slot handler because the function return would be ... undefined? (Interestingly, it doesn't seem to blow up on me though.) So I've used boost:shared_ptr along with shared_from_this to make sure the client doesn't get deleted until all slots have been signaled. It doesn't seem to really matter though. I believe this question is not specific to ASIO, but the problem manifests in a peculiar way when using ASIO. I have one thread executing io_service.run(). All ASIO read/write operations are performed asynchronously. Everything works fine with multiple clients connecting/disconnecting UNLESS I delete my client object from the Set per the code above. If I delete my client object, the io_service seemingly deadlocks internally and no further asynchronous operations are performed unless I start another thread. I have try/catches around the io_service.run() call and have not been able to detect any errors. Questions: Are there best practices for deleting child objects, that are also signal emitters, from within parent slots? Any ideas as to why the io_service is hanging when I delete my network client object?

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  • Windows phone app xaml error

    - by thewarri0r9
    i am developing an app for windows phone 8 and i stuck on this code which visual studio showing invalid xaml. But Code compiles and works well. Invalid xaml Code is : <DataTemplate x:Key="AddrBookItemTemplate"> <StackPanel Margin="0,0,0,2" Orientation="Horizontal"> <StackPanel Width="80" Orientation="Horizontal" Height="80"> <Ellipse Margin="0" Height="70" Width="70" HorizontalAlignment="Left" Stroke="{x:Null}"> <Ellipse.Fill> <ImageBrush Stretch="Fill" ImageSource="{Binding imageBytes, Converter={StaticResource BytesToImageConverter}}"/> </Ellipse.Fill> </Ellipse> </StackPanel> <StackPanel Height="80" Margin="0" Width="380" HorizontalAlignment="Left"> <TextBlock FontWeight="Bold" Text="{Binding FirstName}" FontFamily="Segoe WP Semibold" FontSize="30" VerticalAlignment="Top" Margin="5,0,0,0" HorizontalAlignment="Left" /> <TextBlock Text="{Binding Phone}" FontFamily="Segoe WP" FontSize="24" Foreground="{StaticResource PhoneTextBoxReadOnlyBrush}" Margin="5,0,0,-12" Width="320" HorizontalAlignment="Left" VerticalAlignment="Top"/> </StackPanel> </StackPanel> </DataTemplate> I am serializing image by converting it to byte, it works fine but if image is null it gives an error. code behind: if (e.Results != null) { List<AddressBook> source = new List<AddressBook>(); foreach (var result in e.Results) { if (result.PhoneNumbers.FirstOrDefault() != null && result.GetPicture()!=null) { BitmapImage bmp = new BitmapImage(); BitmapImage nullbmp = new BitmapImage(); if (result.GetPicture() == null) { bmp.UriSource = new Uri(@"/Images/ci2.png", UriKind.RelativeOrAbsolute); } else { bmp.SetSource(result.GetPicture()); } listobj.Add(new AddressBook() { FirstName = result.DisplayName != null ? result.DisplayName : "", imageBytes = AddressBook.imageConvert(bmp), EmailAddress = "", LastName = "", Phone = result.PhoneNumbers.FirstOrDefault() != null ? result.PhoneNumbers.FirstOrDefault().PhoneNumber : "", }); } } Above code show an error "object reference not set to instance of an object". I want to show the default image (or color) in ellipse when image is null.What should I do?

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  • .NET and C# Exceptions. What is it reasonable to catch.

    - by djna
    Disclaimer, I'm from a Java background. I don't do much C#. There's a great deal of transfer between the two worlds, but of course there are differences and one is in the way Exceptions tend to be thought about. I recently answered a C# question suggesting that under some circstances it's reasonable to do this: try { some work } catch (Exeption e) { commonExceptionHandler(); } (The reasons why are immaterial). I got a response that I don't quite understand: until .NET 4.0, it's very bad to catch Exception. It means you catch various low-level fatal errors and so disguise bugs. It also means that in the event of some kind of corruption that triggers such an exception, any open finally blocks on the stack will be executed, so even if the callExceptionReporter fuunction tries to log and quit, it may not even get to that point (the finally blocks may throw again, or cause more corruption, or delete something important from the disk or database). May I'm more confused than I realise, but I don't agree with some of that. Please would other folks comment. I understand that there are many low level Exceptions we don't want to swallow. My commonExceptionHandler() function could reasonably rethrow those. This seems consistent with this answer to a related question. Which does say "Depending on your context it can be acceptable to use catch(...), providing the exception is re-thrown." So I conclude using catch (Exception ) is not always evil, silently swallowing certain exceptions is. The phrase "Until .NET 4 it is very bad to Catch Exception" What changes in .NET 4? IS this a reference to AggregateException, which may give us some new things to do with exceptions we catch, but I don't think changes the fundamental "don't swallow" rule. The next phrase really bothers be. Can this be right? It also means that in the event of some kind of corruption that triggers such an exception, any open finally blocks on the stack will be executed (the finally blocks may throw again, or cause more corruption, or delete something important from the disk or database) My understanding is that if some low level code had lowLevelMethod() { try { lowestLevelMethod(); } finally { some really important stuff } } and in my code I call lowLevel(); try { lowLevel() } catch (Exception e) { exception handling and maybe rethrowing } Whether or not I catch Exception this has no effect whatever on the excution of the finally block. By the time we leave lowLevelMethod() the finally has already run. If the finally is going to do any of the bad things, such as corrupt my disk, then it will do so. My catching the Exception made no difference. If It reaches my Exception block I need to do the right thing, but I can't be the cause of dmis-executing finallys

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  • Gradual memory leak in loop over contents of QTMovie

    - by Benji XVI
    I have a simple foundation tool that exports every frame of a movie as a .tiff file. Here is the relevant code: NSString* movieLoc = [NSString stringWithCString:argv[1]]; QTMovie *sourceMovie = [QTMovie movieWithFile:movieLoc error:nil]; int i=0; while (QTTimeCompare([sourceMovie currentTime], [sourceMovie duration]) != NSOrderedSame) { // save image of movie to disk NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSString *filePath = [NSString stringWithFormat:@"/somelocation_%d.tiff", i++]; NSData *currentImageData = [[sourceMovie currentFrameImage] TIFFRepresentation]; [currentImageData writeToFile:filePath atomically:NO]; NSLog(@"%@", filePath); [sourceMovie stepForward]; [arp release]; } [pool drain]; return 0; As you can see, in order to prevent very large memory buildups with the various transparently-autoreleased variables in the loop, we create, and flush, an autoreleasepool with every run through the loop. However, over the course of stepping through a movie, the amount of memory used by the program still gradually increases. Instruments is not detecting any memory leaks per se, but the object trace shows certain General Data blocks to be increasing in size. [Edited out reference to slowdown as it doesn't seem to be as much of a problem as I thought.] Edit: let's knock out some parts of the code inside the loop & see what we find out... Test 1 while (banana) { NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSString *filePath = [NSString stringWithFormat:@"/somelocation_%d.tiff", i++]; NSLog(@"%@", filePath); [sourceMovie stepForward]; [arp release]; } Here we simply loop over the whole movie, creating the filename and logging it. Memory characteristics: remains at 15MB usage for the duration. Test 2 while (banana) { NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSImage *image = [sourceMovie currentFrameImage]; [sourceMovie stepForward]; [arp release]; } Here we add back in the creation of the NSImage from the current frame. Memory characteristics: gradually increasing memory usage. RSIZE is at 60MB by frame 200; 75MB by f300. Test 3 while (banana) { NSAutoreleasePool *arp = [[NSAutoreleasePool alloc] init]; NSImage *image = [sourceMovie currentFrameImage]; NSData *imageData = [image TIFFRepresentation]; [sourceMovie stepForward]; [arp release]; } We've added back in the creation of an NSData object from the NSImage. Memory characteristics: Memory usage is again increasing: 62MB at f200; 75MB at f300. In other words, largely identical. It looks like a memory leak in the underlying system QTMovie uses to do currentFrameImage, to me.

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  • How to handle ordering of @Rule's when they are dependant on eachother

    - by Lennart Schedin
    I use embedded servers that run inside Junit test cases. Sometimes these servers require a working directory (for example the Apache Directory server). The new @Rule in Junit 4.7 can handle these cases. The TemporaryFolder-Rule can create a temporary directory. A custom ExternalResource-Rule can be created for server. But how do I handle if I want to pass the result from one rule into another: import static org.junit.Assert.assertEquals; import java.io.*; import org.junit.*; import org.junit.rules.*; public class FolderRuleOrderingTest { @Rule public TemporaryFolder folder = new TemporaryFolder(); @Rule public MyNumberServer server = new MyNumberServer(folder); @Test public void testMyNumberServer() throws IOException { server.storeNumber(10); assertEquals(10, server.getNumber()); } /** Simple server that can store one number */ private static class MyNumberServer extends ExternalResource { private TemporaryFolder folder; /** The actual datafile where the number are stored */ private File dataFile; public MyNumberServer(TemporaryFolder folder) { this.folder = folder; } @Override protected void before() throws Throwable { if (folder.getRoot() == null) { throw new RuntimeException("TemporaryFolder not properly initialized"); } //All server data are stored to a working folder File workingFolder = folder.newFolder("my-work-folder"); dataFile = new File(workingFolder, "datafile"); } public void storeNumber(int number) throws IOException { dataFile.createNewFile(); DataOutputStream out = new DataOutputStream(new FileOutputStream(dataFile)); out.writeInt(number); } public int getNumber() throws IOException { DataInputStream in = new DataInputStream(new FileInputStream(dataFile)); return in.readInt(); } } } In this code the folder is sent as a parameter into the server so that the server can create a working directory to store data. However this does not work because Junit processes the rules in reverse order as they are defined in the file. The TemporaryFolder Rule will not be executed before the server Rule. Thus the root-folder in TempraryFolder will be null, resulting that any files are created relative to the current working directory. If I reverse the order of the attributes in my class I get a compile error because I cannot reference a variable before it is defined. I'm using Junit 4.8.1 (because the ordering of rules was fixed a bit from the 4.7 release)

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  • Convert NSData into Hex NSString

    - by Dawson
    With reference to the following question: Convert NSData into HEX NSSString I have solved the problem using the solution provided by Erik Aigner which is: NSData *data = ...; NSUInteger capacity = [data length] * 2; NSMutableString *stringBuffer = [NSMutableString stringWithCapacity:capacity]; const unsigned char *dataBuffer = [data bytes]; NSInteger i; for (i=0; i<[data length]; ++i) { [stringBuffer appendFormat:@"%02X", (NSUInteger)dataBuffer[i]]; } However, there is one small problem in that if there are extra zeros at the back, the string value would be different. For eg. if the hexa data is of a string @"3700000000000000", when converted using a scanner to integer: unsigned result = 0; NSScanner *scanner = [NSScanner scannerWithString:stringBuffer]; [scanner scanHexInt:&result]; NSLog(@"INTEGER: %u",result); The result would be 4294967295, which is incorrect. Shouldn't it be 55 as only the hexa 37 is taken? So how do I get rid of the zeros? EDIT: (In response to CRD) Hi, thanks for clarifying my doubts. So what you're doing is to actually read the 64-bit integer directly from a byte pointer right? However I have another question. How do you actually cast NSData to a byte pointer? To make it easier for you to understand, I'll explain what I did originally. Firstly, what I did was to display the data of the file which I have (data is in hexadecimal) NSData *file = [NSData dataWithContentsOfFile:@"file path here"]; NSLog(@"Patch File: %@",file); Output: Next, what I did was to read and offset the first 8 bytes of the file and convert them into a string. // 0-8 bytes [file seekToFileOffset:0]; NSData *b = [file readDataOfLength:8]; NSUInteger capacity = [b length] * 2; NSMutableString *stringBuffer = [NSMutableString stringWithCapacity:capacity]; const unsigned char *dataBuffer = [b bytes]; NSInteger i; for (i=0; i<[b length]; ++i) { [stringBuffer appendFormat:@"%02X", (NSUInteger)dataBuffer[i]]; } NSLog(@"0-8 bytes HEXADECIMAL: %@",stringBuffer); As you can see, 0x3700000000000000 is the next 8 bytes. The only changes I would have to make to access the next 8 bytes would be to change the value of SeekFileToOffset to 8, so as to access the next 8 bytes of data. All in all, the solution you gave me is useful, however it would not be practical to enter the hexadecimal values manually. If formatting the bytes as a string and then parsing them is not the way to do it, then how do I access the first 8 bytes of the data directly and cast them into a byte pointer?

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  • how to send put request with data as an xml element, from JavaScript ?

    - by Sarang
    Hi everyone, My data is an xml element & I want send PUT request with JavaScript. How do I do this ? For reference : Update Cell As per fredrik suggested, I did this : function submit(){ var xml = "<entry>" + "<id>https://spreadsheets.google.com/feeds/cells/0Aq69FHX3TV4ndDBDVFFETUFhamc5S25rdkNoRkd4WXc/od6/private/full/R2C1</id>" + "<link rel=\"edit\" type=\"application/atom+xml\"" + "href=\"https://spreadsheets.google.com/feeds/cells/0Aq69FHX3TV4ndDBDVFFETUFhamc5S25rdkNoRkd4WXc/worksheetId/private/full/R2C1\"/>" + "<gs:cell row=\"2\" col=\"1\" inputValue=\"300\"/>" + "</entry>"; document.getElementById('submitForm').submit(xml); } </script> </head> <body> <form id="submitForm" method="put" action="https://spreadsheets.google.com/feeds/cells/0Aq69FHX3TV4ndDBDVFFETUFhamc5S25rdkNoRkd4WXc/od6/private/full/R2C1"> <input type="submit" value="submit" onclick="submit()"/> </form> However, it doesn't write back but positively it returns xml file like : <?xml version='1.0' encoding='UTF-8'?> <entry xmlns='http://www.w3.org/2005/Atom' xmlns:gs='http://schemas.google.com/spreadsheets/2006' xmlns:batch='http://schemas.google.com/gdata/batch'> <id>https://spreadsheets.google.com/feeds/cells/0Aq69FHX3TV4ndDBDVFFETUFhamc5S25rdkNoRkd4WXc/od6/private/full/R2C1</id> <updated>2011-01-11T07:35:09.767Z</updated> <category scheme='http://schemas.google.com/spreadsheets/2006' term='http://schemas.google.com/spreadsheets/2006#cell'/> <title type='text'>A2</title> <content type='text'></content> <link rel='self' type='application/atom+xml' href='https://spreadsheets.google.com/feeds/cells/0Aq69FHX3TV4ndDBDVFFETUFhamc5S25rdkNoRkd4WXc/od6/private/full/R2C1'/> <link rel='edit' type='application/atom+xml' href='https://spreadsheets.google.com/feeds/cells/0Aq69FHX3TV4ndDBDVFFETUFhamc5S25rdkNoRkd4WXc/od6/private/full/R2C1/1ekg'/> <gs:cell row='2' col='1' inputValue=''></gs:cell> </entry> Any further solution for the same ?

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  • Abstract mapping with custom JiBX marshaller

    - by aweigold
    I have created a custom JiBX marshaller and verified it works. It works by doing something like the following: <binding xmlns:tns="http://foobar.com/foo" direction="output"> <namespace uri="http://foobar.com/foo" default="elements"/> <mapping class="java.util.HashMap" marshaller="com.foobar.Marshaller1"/> <mapping name="context" class="com.foobar.Context"> <structure field="configuration"/> </mapping> </binding> However I need to create multiple marshallers for different HashMaps. So I tried to reference it with abstract mapping like this: <binding xmlns:tns="http://foobar.com/foo" direction="output"> <namespace uri="http://foobar.com/foo" default="elements"/> <mapping abstract="true" type-name="configuration" class="java.util.HashMap" marshaller="com.foobar.Marshaller1"/> <mapping abstract="true" type-name="overrides" class="java.util.HashMap" marshaller="com.foobar.Marshaller2"/> <mapping name="context" class="com.foobar.Context"> <structure map-as="configuration" field="configuration"/> <structure map-as="overrides" field="overrides"/> </mapping> </binding> However when doing so, when I attempt to build the binding, I receive the following: Error during code generation for file "E:\project\src\main\jibx\foo.jibx" - this may be due to an error in your binding or classpath, or to an error in the JiBX code My guess is that either I'm missing something I need to implement to enable my custom marshaller for abstract mapping, or custom marshallers do not support abstract mapping. I have found the IAbstractMarshaller interface in the JiBX API (http://jibx.sourceforge.net/api/org/jibx/runtime/IAbstractMarshaller.html), however the documentation seems unclear to me on if this is what I need to implement, as well as how it works if so. I have not been able to find an implementation of this interface to work off of as an example. My question is, how do you do abstract mapping with custom marshallers (if it's possible)? If it is done via the IAbstractMarshaller interface, how does it work and/or how should I implement it?

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  • Ajax problem after deleting a div, then creating a new one

    - by Matt Nathanson
    I'm building a custom CMS where you can add and delete clients using ajax and jquery 1.4.2. My problem lies after I delete a div. The ajax is used to complete this and refresh automatically.. But when I go to create a new div (without a hard refresh) it puts it back in the slot of the div I just deleted. How can I get this to completely forget about the div i just deleted and place the new div in the next database table? link for reference: http://staging.sneakattackmedia.com/cms/ //Add New client // function AddNewClient() { dataToLoad = 'addClient=yes'; $.ajax({ type: 'post', url: '/clients/controller.php', datatype: 'html', data: dataToLoad, target: ('#clientssidebar'), async: false, success: function(html){ $(this).click(function() {reInitialize()}); //$('#clientssidebar').html(html); $('div#' + clientID).slideDown(800); $(this).click(function() { ExpandSidebar()});}, error: function() { alert('An error occured! 222');} });}; //Delete Client // function DeleteClient(){ var yes = confirm("Whoa there chief! Do you really want to DELETE this client?"); if (yes == 1) { dataToLoad = 'clientID=' + clientID + '&deleteClient=yes', $.ajax({ type: 'post', url: '/clients/controller.php', datatype: 'html', data: dataToLoad, success: function(html) { alert('Client' + clientID + ' should have been deleted from the database.'); $(this).click(function() {reInitialize()}); $('div#' +clientID).slideUp(800); }, error: function() { alert('error'); }});};}; //Re Initialize // function reInitialize() { $('#addnew').click(function() {AddNewClient()}); $('.deletebutton').click(function() {clientID = $(this).parent().attr('id'); DeleteClient()}) $('.clientblock').click(function() {clientID = $(this).attr('id'); ExpandSidebar()});}; //Document Ready // $(document).ready(function(){ if ($('isCMS')){ editCMS = 1; $('.deletebutton').click(function() {clientID = $(this).parent().attr('id'); DeleteClient()}); $('#addnew').click(function() {AddNewClient()}); $('.clientblock').click(function() {clientID = $(this).attr('id'); ExpandSidebar()}); $('.clientblock').click(function() {if (clickClient ==true) { $(this).css('background-image', 'url(/images/highlightclient.png)'); $(this).css('margin-left' , '30px'); }; $(this).click(function(){ $(this).css('background-image', ''); }); $('.uploadbutton').click(function(){UploadThings()}); }); } else ($('#clientscontainer')) { $('#editbutton').css('display', 'none'); }; }); Please help!!!

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  • Deserialization error in a new environment

    - by cerhart
    I have a web application that calls a third-party web service. When I run it locally, I have no problems, but when I move it to my production environment, I get the following error: There is an error in XML document (2, 428). Stack: at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events) at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle) at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall) at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters) at RMXClasses.RMXContactService.ContactService.getActiveSessions(String user, String pass) in C:\Users\hp\Documents\Visual Studio 2008\Projects\ReklamStore\RMXClasses\Web References\RMXContactService\Reference.cs:line 257 at I have used the same web config file from the production environment but it still works locally. My local machine is a running vista home edition and the production environment is windows server 2003. The application is written in asp.net 3.5, wierdly under the asp.net config tab in iis, 3.5 doesn't show up in the drop down list, although that version of the framework is installed. The error is not being thrown in my code, it happens during serialization. I called the method on the proxy, I have checked the arguments and they are OK. I have also logged the SOAP request and response, and they both look OK as well. I am really at a loss here. Any ideas? SOAP log: This is the soap response that the program seems to have trouble parsing only on server 2003. On my machine the soap is identical, and yet it parses with no problems. SoapResponse BeforeDeserialize; <?xml version="1.0" encoding="UTF-8"?> <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="urn:ContactService" xmlns:ns2="http://api.yieldmanager.com/types" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"><SOAP-ENV:Body><ns1:getActiveSessionsResponse> <sessions SOAP-ENC:arrayType="ns2:session[1]" xsi:type="ns2:array_of_session"> <item xsi:type="ns2:session"> <token xsi:type="xsd:string">xxxxxxxxxxxxxxxxxxxx1ae12517584b</token> <creation_time xsi:type="xsd:dateTime">2009-09-25T05:51:19Z</creation_time> <modification_time xsi:type="xsd:dateTime">2009-09-25T05:51:19Z</modification_time> <ip_address xsi:type="xsd:string">xxxxxxxxxx</ip_address> <contact_id xsi:type="xsd:long">xxxxxx</contact_id></item></sessions> </ns1:getActiveSessionsResponse></SOAP-ENV:Body></SOAP-ENV:Envelope>

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  • How To Load Images into Custom UITableViewCell?

    - by Clifton Burt
    This problem is simple, but crucial and urgent. Here's what needs to be done: load 66px x 66px images into the table cells in the MainViewController table. each TableCell has a unique image. But how? Would we use cell.image?... cell.image = [UIImage imageNamed:@"image.png"]; If so, where? Is an if/else statement required? Help? Here's the project code, hosted on Google Code, for easy and quick reference... http://www.google.com/codesearch/p?hl=en#Fcn2OtVUXnY/trunk/apple-sample-code/NavBar/NavBar/MyCustomCell.m&q=MyCustomCell%20lang:objectivec To load each cell's labels, MainViewController uses an NSDictionary and NSLocalizedString like so... //cell one menuList addObject:[NSDictionary dictionaryWithObjectsAndKeys: NSLocalizedString(@"PageOneTitle", @""), kTitleKey, NSLocalizedString(@"PageOneExplain", @""), kExplainKey, nil]]; //cell two menuList addObject:[NSDictionary dictionaryWithObjectsAndKeys: NSLocalizedString(@"PageOneTitle", @""), kTitleKey, NSLocalizedString(@"PageOneExplain", @""), kExplainKey, nil]]; ... // this is where MainViewController loads the cell content - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { MyCustomCell *cell = (MyCustomCell*)[tableView dequeueReusableCellWithIdentifier:kCellIdentifier]; if (cell == nil) { cell = [[[MyCustomCell alloc] initWithFrame:CGRectZero reuseIdentifier:kCellIdentifier] autorelease]; } ... // MyCustomCell.m adds the subviews - (id)initWithFrame:(CGRect)aRect reuseIdentifier:(NSString *)identifier { self = [super initWithFrame:aRect reuseIdentifier:identifier]; if (self) { // you can do this here specifically or at the table level for all cells self.accessoryType = UITableViewCellAccessoryDisclosureIndicator; // Create label views to contain the various pieces of text that make up the cell. // Add these as subviews. nameLabel = [[UILabel alloc] initWithFrame:CGRectZero]; // layoutSubViews will decide the final frame nameLabel.backgroundColor = [UIColor clearColor]; nameLabel.opaque = NO; nameLabel.textColor = [UIColor blackColor]; nameLabel.highlightedTextColor = [UIColor whiteColor]; nameLabel.font = [UIFont boldSystemFontOfSize:18]; [self.contentView addSubview:nameLabel]; explainLabel = [[UILabel alloc] initWithFrame:CGRectZero]; // layoutSubViews will decide the final frame explainLabel.backgroundColor = [UIColor clearColor]; explainLabel.opaque = NO; explainLabel.textColor = [UIColor grayColor]; explainLabel.highlightedTextColor = [UIColor whiteColor]; explainLabel.font = [UIFont systemFontOfSize:14]; [self.contentView addSubview:explainLabel]; //added to mark where the thumbnail image should go imageView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 66, 66)]; [self.contentView addSubview:imageView]; } return self; } HELP?

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  • Memory Leak with Swing Drag and Drop

    - by tom
    I have a JFrame that accepts top-level drops of files. However after a drop has occurred, references to the frame are held indefinitely inside some Swing internal classes. I believe that disposing of the frame should release all of its resources, so what am I doing wrong? Example import java.awt.datatransfer.DataFlavor; import java.io.File; import java.util.List; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.TransferHandler; public class DnDLeakTester extends JFrame { public static void main(String[] args) { new DnDLeakTester(); //Prevent main from returning or the jvm will exit while (true) { try { Thread.sleep(10000); } catch (InterruptedException e) { } } } public DnDLeakTester() { super("I'm leaky"); add(new JLabel("Drop stuff here")); setTransferHandler(new TransferHandler() { @Override public boolean canImport(final TransferSupport support) { return (support.isDrop() && support .isDataFlavorSupported(DataFlavor.javaFileListFlavor)); } @Override public boolean importData(final TransferSupport support) { if (!canImport(support)) { return false; } try { final List<File> files = (List<File>) support.getTransferable().getTransferData(DataFlavor.javaFileListFlavor); for (final File f : files) { System.out.println(f.getName()); } } catch (Exception e) { e.printStackTrace(); } return true; } }); setDefaultCloseOperation(DISPOSE_ON_CLOSE); pack(); setVisible(true); } } To reproduce, run the code and drop some files on the frame. Close the frame so it's disposed of. To verify the leak I take a heap dump using JConsole and analyse it with the Eclipse Memory Analysis tool. It shows that sun.awt.AppContext is holding a reference to the frame through its hashmap. It looks like TransferSupport is at fault. What am I doing wrong? Should I be asking the DnD support code to clean itself up somehow? I'm running JDK 1.6 update 19.

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  • LINQ Except operator and object equality

    - by Abhijeet Patel
    Here is an interesting issue I noticed when using the Except Operator: I have list of users from which I want to exclude some users: The list of users is coming from an XML file: The code goes like this: interface IUser { int ID { get; set; } string Name { get; set; } } class User: IUser { #region IUser Members public int ID { get; set; } public string Name { get; set; } #endregion public override string ToString() { return ID + ":" +Name; } public static IEnumerable<IUser> GetMatchingUsers(IEnumerable<IUser> users) { IEnumerable<IUser> localList = new List<User> { new User{ ID=4, Name="James"}, new User{ ID=5, Name="Tom"} }.OfType<IUser>(); var matches = from u in users join lu in localList on u.ID equals lu.ID select u; return matches; } } class Program { static void Main(string[] args) { XDocument doc = XDocument.Load("Users.xml"); IEnumerable<IUser> users = doc.Element("Users").Elements("User").Select (u => new User { ID = (int)u.Attribute("id"), Name = (string)u.Attribute("name") } ).OfType<IUser>(); //still a query, objects have not been materialized var matches = User.GetMatchingUsers(users); var excludes = users.Except(matches); // excludes should contain 6 users but here it contains 8 users } } When I call User.GetMatchingUsers(users) I get 2 matches as expected. The issue is that when I call users.Except(matches) The matching users are not being excluded at all! I am expecting 6 users ut "excludes" contains all 8 users instead. Since all I'm doing in GetMatchingUsers(IEnumerable users) is taking the IEnumerable and just returning the IUsers whose ID's match( 2 IUsers in this case), my understanding is that by default "Except" will use reference equality for comparing the objects to be excluded. Is this not how "Except" behaves? What is even more interesting is that if I materialize the objects using .ToList() and then get the matching users, and call "Except", everything works as expected! Like so: IEnumerable users = doc.Element("Users").Elements("User").Select (u = new User { ID = (int)u.Attribute("id"), Name = (string)u.Attribute("name") } ).OfType().ToList(); //explicity materializing all objects by calling ToList() var matches = User.GetMatchingUsers(users); var excludes = users.Except(matches); // excludes now contains 6 users as expected I don't see why I should need to materialize objects for calling "Except" given that its defined on IEnumerable? Any suggesstions / insights would be much appreciated.

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  • jquery, manipulate content inserted by ajax, without using the callback

    - by Cody
    I am using ajax to insert a series of informational blocks via a loop. The blocks each have a title, and long description in them that is hidden by default. They function like an accordion, only showing one description at a time amongst all of the blocks. The problem is opening the description on the first block. I would REALLY like to do it with javascript right after the loop that is creating them is done. Is it possible to manipulate elements created ofter an ajax call without using the callback? <!-- example code--> <style> .placeholder, .long_description{ display:none;} </style> </head><body> <script> /* yes, this script is in the body, dont know if it matters */ $(document).ready(function() { $(".placeholder").each(function(){ // Use the divs to get the blocks var blockname = $(this).html(); // the contents if the div is the ID for the ajax POST $.post("/service_app/dyn_block",'form='+blockname, function(data){ var divname = '#div_' + blockname; $(divname).after(data); $(this).setupAccrdFnctly(); //not the actual code }); }); /* THIS LINE IS THE PROBLEM LINE, is it possible to reference the code ajax inserted */ /* Display the long description in the first dyn_block */ $(".dyn_block").first().find(".long_description").addClass('active').slideDown('fast'); }); </script> <!-- These lines are generated by PHP --> <!-- It is POSSIBLE to display the dyn_blocks --> <!-- here but I would really rather not --> <div id="div_servicetype" class="placeholder">servicetype</div> <div id="div_custtype" class="placeholder">custtype</div> <div id="div_custinfo" class="placeholder">custinfo</div> <div id="div_businfo" class="placeholder">businfo</div> </body>

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  • Do You Really Know Your Programming Languages?

    - by Kristopher Johnson
    I am often amazed at how little some of my colleagues know or care about their craft. Something that constantly frustrates me is that people don't want to learn any more than they need to about the programming languages they use every day. Many programmers seem content to learn some pidgin sub-dialect, and stick with that. If they see a keyword or construct that they aren't familiar with, they'll complain that the code is "tricky." What would you think of a civil engineer who shied away from calculus because it had "all those tricky math symbols?" I'm not suggesting that we all need to become "language lawyers." But if you make your living as a programmer, and claim to be a competent user of language X, then I think at a minimum you should know the following: Do you know the keywords of the language and what they do? What are the valid syntactic forms? How are memory, files, and other operating system resources managed? Where is the official language specification and library reference for the language? The last one is the one that really gets me. Many programmers seem to have no idea that there is a "specification" or "standard" for any particular language. I still talk to people who think that Microsoft invented C++, and that if a program doesn't compile under VC6, it's not a valid C++ program. Programmers these days have it easy when it comes to obtaining specs. Newer languages like C#, Java, Python, Ruby, etc. all have their documentation available for free from the vendors' web sites. Older languages and platforms often have standards controlled by standards bodies that demand payment for specs, but even that shouldn't be a deterrent: the C++ standard is available from ISO for $30 (and why am I the only person I know who has a copy?). Programming is hard enough even when you do know the language. If you don't, I don't see how you have a chance. What do the rest of you think? Am I right, or should we all be content with the typical level of programming language expertise? Update: Several great comments here. Thanks. A couple of people hit on something that I didn't think about: What really irks me is not the lack of knowledge, but the lack of curiosity and willingness to learn. It seems some people don't have any time to hone their craft, but they have plenty of time to write lots of bad code. And I don't expect people to be able to recite a list of keywords or EBNF expressions, but I do expect that when they see some code, they should have some inkling of what it does. Few people have complete knowledge of every dark corner of their language or platform, but everyone should at least know enough that when they see something unfamiliar, they will know how to get whatever additional information they need to understand it.

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  • My mental block - struggling to learn Objective C

    - by iqessar
    Hello people, this would be my first question after signing up! Anyway heres my question, I did Java at university and I was always told I am a good programmer. However I never pursued it as a career - I went into support and management instead. Im pretty much bored with my job, I have therefore started to learn Objective C so that I can develop apps for the iphone. I am currently watching several different Videos / Books. My problem is that when I go through the Apple documentation, although I understand most of it, sometimes I stumble. I believe that because you/we have the Apple documentation (i.e. Framework references) , everything should be clear, and therefore you should have no need to refer to a book or video (in order to learn how to use a particular class). But I alway do refer to a book and video and subsequently feel guilty as I believe the framework reference should be enough. (I therefore feel I am not up to being a programmer) I also believe that you shouldn't need example code in order to learn how to use a particular class because Apple provides documentation for each class, but AGAIN I find my self googling example code and I find my answer like that - again I feel guilty for doing this. Am I right in saying that Apple documentation is simply not clear? and that its ok to refer to a video/book or google? or forums for that matter? I have proffesional programmers who tell me that I am worrying too much and that I should get on with it and use all the resources that I have. I just cant seem to get round this mental block that I have in my head. When I start a programming project I am able to use the excellent search skills that I have to find the code I need, copy and paste it (yes I do understand it) BUT then I feel guilty telling myself that why didn't you think up the code yourself???? Therefore your not a real programmer, your just good at googling. Currently I am going through 20+ books so that I can learn most of the frameworks, syntax etc to develop iphone apps. I believe if I do this, then when I think of a project I can make it quickly. Should I read a few books, like 2-3 and then just start a project /app , and if I get stuck just google it and get the code I need? Can anybody please answer my questions?

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  • Nested form problem in Rails : NoMethodError in Show

    - by brianheys
    I'm trying to build a simple product backlog application to teach myself Rails. For each product, there can be multiple product backlog entries, so I want to create a product view that shows the product information, all the backlog entries for the product, and includes a nested form for adding more backlog entries. Everything works until I try to add the form to the view, which then results in the following error: NoMethodError in Products#show Showing app/views/products/show.html.erb where line #29 raised: undefined method `pblog_ref' for #<Product:0x10423ba68> Extracted source (around line #29): 26: <%= f.error_messages %> 27: <p> 28: <%= f.label :pblog_ref %><br /> 29: <%= f.text_field :pblog_ref %> 30: </p> 31: <p> 32: <%= f.label :product %><br /> The product view where the problem is reported is as follows (the partial works fine, so I won't include that code): <h1>Showing product</h1> <p> <b>Product ref:</b> <%=h @product.product_ref %> </p> <p> <b>Description:</b> <%=h @product.description %> </p> <p> <b>Owner:</b> <%=h @product.owner %> </p> <p> <b>Status:</b> <%=h @product.status %> </p> <h2>Product backlog</h2> <div id="product-backlog"> <%= render :partial => @product.product_backlogs %> </div> <% form_for(@product, ProductBacklog.new) do |f| %> <%= f.error_messages %> <p> <%= f.label :pblog_ref %><br /> <%= f.text_field :pblog_ref %> </p> <p> <%= f.label :product %><br /> <%= f.text_field :product %> </p> <p> <%= f.label :description %><br /> <%= f.text_field :description %> </p> <p> <%= f.label :owner %><br /> <%= f.text_field :owner %> </p> <p> <%= f.label :status %><br /> <%= f.text_field :status %> </p> <p> <%= f.submit 'Create' %> </p> <% end %> <%= link_to 'Edit', edit_product_path(@product) %> | <%= link_to 'Back', products_path %> This is the Product model: class Product < ActiveRecord::Base validates_presence_of :product_ref, :description, :owner has_many :product_backlogs end This is the ProductBacklog model: class ProductBacklog < ActiveRecord::Base belongs_to :product end These are the routes: map.resources :product_backlogs map.resources :products, :has_many => :product_backlogs I've checked what I'm doing against the Creating a weblog in 15 minutes with Rails 2 screencast, and in principle I seem to be doing the same thing as him - only his nested comments form works, and mine doesn't! I hope someone can help with this, before I turn mad! I'm sure it's something trivial.

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  • Few doubts regarding Bitmaps , Images & `using` blocks

    - by imageWorker
    I caught up in this problem. http://stackoverflow.com/questions/2559826/garbage-collector-not-doing-its-job-memory-consumption-1-5gb-outofmemory-exc I feel that there is something wrong in my understanding. Please clarify these things. Destructor & IDisposable.Dispose are two methods for freeing resources that are not not under the control of .NET. Which means, everything except memory. right? using blocks are just better way of calling IDisposable.Dispose() method of an object. This is the main code I'm referring to. class someclass { static someMethod(Bitmap img) { Bitmap bmp = new Bitmap(img); //statement1 // some code here and return } } here is class I'm using for testing: class someotherClass { public static voide Main() { foreach (string imagePath in imagePathsArray) { using (Bitmap img1 = new Bitmap(imagePath)) { someclass.someMethod(img1); // does some more processing on `img1` } } } } Is there any memory leak with statement1? Question1: If each image size is say 10MB. Then does this bmp object occupy atleast 10MB? What I mean is, will it make completely new copy of entire image? or just refer to it? Question2:should I or should I not put the statement1 in using block? My Argument: We should not. Because using is not for freeing memory but for freeing the resources (file handle in this case). If I use it in using block. It closes file handle here encapsulated by this bmp object. It means we are also closing filehandle for the caller's img1 object. Which is not correct? As of the memory leak. No there is no scope of memory leak here. Because reference bmp is destroyed when this method is returned. Which leaves memory it refered without any pointer. So, its garbage collected. Am I right? Edit: class someclass { static Bitmap someMethod(Bitmap img) { Bitmap bmp = new Bitmap(img); //can I use `using` block on this enclosing `return bmp`; ??? // do some processing on bmp here return bmp; } }

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  • Can't access font resource in Silverlight class library

    - by Matt
    I have a reasonably large Silveright 3.0 project on the go, and I'm having issues accessing a couple of custom font resources from within one of the assemblies. I've got a working test solution where I have added a custom font as a resource, and can access it fine from XAML using: <TextBlock Text="Test" FontFamily="FontName.ttf#Font Name" /> The test solution consists of the TestProject.Application and the TestProject.Application.Web projects, with all the fun and games obviously in the TestProject.Application project However, when I try this in my main solution, the fonts refuse to show in the correct type face (instead showing in the default font). There's no difference in the way the font has been added to project between the test solution and the main solution, and the XAML is identical. However, there is a solution layout difference. In the main solution, as well as having a MainApp.Application and MainApp.Application.Web project, I also have a MainApp.Application.ViewModel project and a MainApp.Application.Views project, and the problem piece of XAML is the in the MainApp.Application.Views project (not the .Application project like the test solution). I've tried putting the font into either the .Application or .Application.Views project, tried changing the Build Action to Content, Embedded Resource etc, all to no avail. So, is there an issue accessing font resources from a child assembly that I don't know about, or has anyone successfully done this? My long term need will be to have the valid custom fonts being stored as resources in a separate .Application.FontLibrary assembly that will be on-demand downloaded and cached, and the XAML controls in the .Application.Views project will need to reference this FontLibrary assembly to get the valid fonts. I've also tried xcreating this separate font library assembly, and I can't seem to get the fonts from the second assembly. As some additional information, I've also tried the following font referencing approaches: <TextBlock Text="Test" FontFamily="/FontName.ttf#Font Name" /> <TextBlock Text="Test" FontFamily="pack:application,,,/FontName.ttf#Font Name" /> <TextBlock Text="Test" FontFamily="pack:application,,,/MainApp.Application.Views;/FontName.ttf#Font Name" /> <TextBlock Text="Test" FontFamily="pack:application,,,/MainApp.Application.Views;component/FontName.ttf#Font Name" /> And a few similar variants with different assembly references/sub directories/random semi colons. And so far nothing works... anyone struck this (and preferably solved it)?

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