Question

I have two datatemplates defined as static resources. Now I have a combobox with each of those names. Is it possible to have your controls utilizing these staticresources as itemtemplates to bind to the name of the selected static resource in the combobox?

Thanks in advance.

Answer 1

Here is something that looks quite insane but works reasonably well.

<Grid x:Name="LayoutRoot">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
    </Grid.RowDefinitions>
    <ComboBox x:Name="cboTemplate" DisplayMemberPath="Key" SelectedValuePath="Key" SelectedValue="Blue">
        <ComboBox.ItemsSource>
            <ResourceDictionary>
                <DataTemplate x:Key="Blue">
                    <TextBlock Foreground="Blue" Text="{Binding}" />
                </DataTemplate>
                <DataTemplate x:Key="Red">
                    <TextBlock Foreground="Red" Text="{Binding}" />
                </DataTemplate>
            </ResourceDictionary>
        </ComboBox.ItemsSource>
    </ComboBox>
    <ContentPresenter Grid.Row="1" Content="Hello World" ContentTemplate="{Binding SelectedItem.Value, ElementName=cboTemplate}" />
</Grid>

Resource dictionary is fundementally an collection of the KeyValuePair<object, object>, except Xaml parsing gives use a leg up with populating it using the x:Key attribute. So this ComboBox displays the Key property but its SelectedItem will be the KeyValuePair<object, object> whose Value property is the DataTemplate we want. We can now use element to element binding on a ContentTemplate or an ItemTemplate property.

If you also need the DataTemplates available as static resources and you want to avoid code duplication you can place them in a separate resource dictionary xaml file. You can then use:-

        <ComboBox.ItemsSource>
            <ResourceDictionary Source="DataTemplateResources.xaml" />
        </ComboBox.ItemsSource>

As well as include them in static resources like:-

 <UserControl.Resources>
     <ResourceDictionary>
          <ResourceDictionary.MergedDictionaries>
               <ResourceDictionary Source="DataTemplateResources.xaml" />
          </ResourceDictionary.MergedDictionaries>
          <!-- other resources here -->
     </ResourceDictionary>
 </UserControl.Resources>