DeferredReference

Question

I am getting this:
A first chance exception of type 'System.InvalidCastException' occurred in WindowsBase.dll
An unhandled exception of type 'System.InvalidCastException' occurred in WindowsBase.dll

Additional information: Unable to cast object of type 'System.Windows.Media.SolidColorBrush' to type 'System.Windows.DeferredReference'.


When changing resource dictionaries to switch between skins, the program crashes but next time it looks fine and works OK (the skin actually changed).

I've seen this other post here:
http://forums.microsoft.com/MSDN/ShowPost.aspx?siteid=1&PostID=3939145

So maybe it is a bug? not sure.

Any solutions or workaround?

Thanks

David

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DCProven

Answer 1

For now,
I am just asking the user to exit the application in order for the new skin to take effect. The skin works perfectly the first time, it's the second time that crashes.

I hate this solution, but I can't find any other way so far.

No other ideas?

Thanks.

David

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DCProven

Answer 2

Could you please provide a small, complete and ready-to-run example to demonstrate the issue you are encountering?

 

Thanks

Answer 3

I am also seeing the same issue. Interestingly it is working fine on one machine and fails on another

Mine is a WPF application, configured to be deployed as click once application. The users getting the exception, do see the other skin being used when they start again as mentioned by David


Further investigation showed that this happens only when vista is running in classic theme and not on vista theme

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MVP Client App

Answer 4

further to previous post, I tried to debug using the symbol server and source code. it poped a dialog asking for path to ExecutionContext.cs (from threading folder), but I could not locate that file (didn't get downloaded). Cancelling it i got the exception displayed on the following code in AppDomain.cs

        [MethodImplAttribute(MethodImplOptions.InternalCall)]

        private extern int _nExecuteAssembly(Assembly assembly, String[] args);

        internal int nExecuteAssembly(Assembly assembly, String[] args)

        {

            return _nExecuteAssembly(assembly.InternalAssembly, args);

        }

Also as I said earlier, this happens when Vista is configured to run with classic theme. Marco, I guess you can take any WPF application that allows you to change skins dynamically at run time and you should be able to see this error

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MVP Client App

Answer 5

Marco,

email me if you want: david AT dolphinimaging DOT com

I'll send you what you need, I can't publish the code here as it is a commercial product, but I'll certainly help you with anything I can.

Again, it seems that when you have a nice enough theme (colors, image files, sizes, ...) changes it happens. It didn't happen when it was just a couple of color changes (first prototype).

Thanks

David.

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DCProven

Answer 6

Okay, I finally come up with a smallest repro code, here it is:

<Window x:Class="SwitchSkinBug.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
  <DockPanel>
    <Menu DockPanel.Dock="Top">
      <MenuItem Header="_View" MenuItem.Click="OnViewMenuItemClick" >
        <MenuItem Header="Red"/>
        <MenuItem Header="Green"/>
        <MenuItem Header="Blue"/>
      </MenuItem>
    </Menu>
    <CheckBox
      Content="Show"
      Foreground="{DynamicResource TextBlock_Foreground}">
      <CheckBox.Template>
        <ControlTemplate TargetType="CheckBox">
          <StackPanel>
            <Path Fill="{TemplateBinding Foreground}"/>
            <ContentPresenter
               Content="{TemplateBinding ContentControl.Content}"/>
          </StackPanel>
        </ControlTemplate>
      </CheckBox.Template>
    </CheckBox>
  </DockPanel>
</Window>

public partial class Window1 : Window
{
    public Window1()
    {
        InitializeComponent();
    }

    private void OnViewMenuItemClick(Object sender, RoutedEventArgs e)
    {
        MenuItem menuItem = e.Source as MenuItem;
        if (menuItem != null)
        {
            Uri uri = new Uri(menuItem.Header + ".xaml", UriKind.Relative);
            ApplySkin(uri);
        }
    }

    private ResourceDictionary loadedDictionary = null;
    public void ApplySkin(Uri uri)
    {
        if (loadedDictionary != null)
        {
            this.Resources.MergedDictionaries.Remove(loadedDictionary);
        }
        ResourceDictionary currentDictionary = Application.LoadComponent(uri) as ResourceDictionary;
        if (currentDictionary != null)
        {
            this.Resources.MergedDictionaries.Add(currentDictionary);
            loadedDictionary = currentDictionary;
        }
    }
}

Here is the Skin dictionary for "Red":
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <SolidColorBrush x:Key="TextBlock_Foreground" Color="Red"/>
</ResourceDictionary>

It seems that you could consistently reproduce this bug if you place a Path and a ContentPresenter inside the control template, and the Path's Fill property is templated bound to the Foreground property as follows:

<ControlTemplate TargetType="CheckBox">
  <StackPanel>
    <Path Fill="{TemplateBinding Foreground}"/>
    <ContentPresenter
       Content="{TemplateBinding ContentControl.Content}"/>
  </StackPanel>
</ControlTemplate>

Both RadioButton and CheckBox has this usage pattern in his own control template, could you please confirm if you are skining the RadioButton or CheckBox controls in your own application?

I would greatly appreciate it if you could file a bug on this at the connect site:

https://connect.microsoft.com/feedback/default.aspx?SiteID=212&wa=wsignin1.0

You could refer to the repro project when feedbacking on this issue at the following link:
http://cid-e9ffaf5298e5a301.skydrive.live.com/self.aspx/Documents/WPF/CodeSamples/SwitchSkinBug.zip

Hope this helps

Answer 7

In my application checkbox or radio button aren't templated like this. What i working on is the Family.Show application (http://www.codeplex.com/familyshow). The application allows you to change the theme between black and silver. if you set a vista machine with classic theme and then try running it, it should give you the error

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MVP Client App

Answer 8

-> if you set a vista machine with classic theme and then try running it, it should give you the error

I don't get any error when running the Family.show demo application.

But the code I pasted above consistently fails both under .NET Framework 3.5 and .NET Framework 3.5 SP1.

Thanks

Answer 9

i guess that is fine, since you have any confirmed that this is a bug

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MVP Client App

Answer 10

Thanks Marco,
I'll file the bug report.

I appreciate your efforts on this one!

David

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DCProven

Answer 11

Well, it's been a year... any progress? Any workarounds?

Edit: Loading the resource in code rather than binding it as a dynamic resource in XAML seems to work.

Answer 12

there is a knowledge base article and hotfix here: 

http://support.microsoft.com/kb/974477