2. Template, Style, Container

Template, Style and Container resolvers example

This example demonstrates the application of DataTemplate, Style, and ItemContainerTemplate to ViewModel items within a WPF application. All definitions are conveniently housed within App.xaml for simplification.

Key Points

1. Registration of Templates, Styles, and Containers:
   In App.xaml.cs, we register data templates, styles, and item container templates to respective ViewModel types using IViewResolverService. This is carried out in the OnStartup method.

   protected override void OnStartup(StartupEventArgs e)
   {
       var viewResolverService = GetViewResolverService();
   
       // Register views in default region
       viewResolverService.AssociateTemplate<Item1ViewModel>((DataTemplate)Resources["Item1DataTemplate"]);
       viewResolverService.AssociateStyle<Item2ViewModel>((Style)Resources["Item2Style"]);
       viewResolverService.AssociateContainer<Item3ViewModel>((ItemContainerTemplate)Resources["Item3ContainerTemplate"]);
   
       base.OnStartup(e);
   }

2. ViewModels Association:
   ViewModel instances are created and associated to the menu within App.xaml.

   <x:Array x:Key="Items" Type="{x:Type system:Object}">
       <viewModels:Item1ViewModel />
       <viewModels:Item2ViewModel />
       <viewModels:Item3ViewModel />
   </x:Array>

3. Template, Style, and Container Definitions:
   Definitions for DataTemplate, Style, and ItemContainerTemplate are done in App.xaml. Each template or style is associated with a ViewModel type.

   <!--  Define Item1ViewModel data template  -->
   <DataTemplate x:Key="Item1DataTemplate" DataType="{x:Type viewModels:Item1ViewModel}">
       <TextBlock Text="{Binding Path=Title}" />
   </DataTemplate>
   
   <!--  Define Item2ViewModel style  -->
   <Style x:Key="Item2Style" TargetType="MenuItem">
       <Setter Property="FontWeight" Value="Bold" />
       <Setter Property="Header" Value="{Binding Path=Title}" />
   </Style>
   
   <!--  Define Item3ViewModel container template  -->
   <ItemContainerTemplate x:Key="Item3ContainerTemplate">
       <RibbonMenuItem Header="{Binding Title}" />
   </ItemContainerTemplate>

4. Menu Configuration:
   The Menu control in MainWindow.xaml is configured to use the defined templates, styles, and containers via ItemTemplateSelector, ItemContainerStyleSelector, and ItemContainerTemplateSelector respectively.

   <Menu HorizontalAlignment="Center"
         VerticalAlignment="Center"
         Background="LightBlue"
         ItemContainerStyleSelector="{mvvm:StyleResolver}"
         ItemContainerTemplateSelector="{mvvm:ContainerResolver}"
         ItemTemplateSelector="{mvvm:TemplateResolver}"
         ItemsSource="{StaticResource Items}"
         UsesItemContainerTemplate="True">
   </Menu>

These configurations demonstrate a clean separation of concerns between the view and the ViewModel, aligning with the MVVM architectural pattern, and simplifying the management of view-related definitions.