Binding to resource key, WPF

I have a ResourceDictionary with some images:

<BitmapImage UriSource="..\Images\Bright\folder-bright.png"
             x:Key="FolderItemImage" />

I've create a HierarchicalTemplate for treeview items like the following:

<HierarchicalDataTemplate ItemsSource="{Binding VisibleChildren}"
                          DataType="{x:Type st:StructureTreeItem}">
    <StackPanel Orientation="Horizontal">
        <TextBlock Text="{Binding ImageResourceKey}" />
        <Image x:Name="iIcon2" Source="{DynamicResource FolderItemImage}"/>
        <Image x:Name="iIcon"
               Source="{DynamicResource {Binding ImageResourceKey}}"/>
    </StackPanel>
</HierarchicalDataTemplate>

Now, when item is displayed:

Textblock displays FolderItemImage
First image is shown
Second image is not shown.

The whole idea is to set item images to ones stored in resources, but the technique presented above unfortunately won't work and now I know, why:

<Image x:Name="iIcon3" Width="16" Height="16" Margin="0, 1, 3, 1" >
    <Image.Source>
        <DynamicResource ResourceKey="{Binding ImageResourceKey}" />
    </Image.Source>
</Image>

Result:

An unhandled exception of type 'System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll

Additional information: A 'Binding' cannot be set on the 'ResourceKey' property of type 'DynamicResourceExtension'. A 'Binding' can only be set on a DependencyProperty of a DependencyObject.

So I have to rephrase my question: how can I convert some data (a resource key, perhaps?) stored in model to a dynamic resource? It has to be a dynamic resource, because I'm certain it may change during runtime.

Binding to resource key, WPF

4 Answers