DataTrigger

In this article I want to extend my ItemsControl.Style, by binding template.

XAML:

<Grid>

	<Grid.Resources>
		<itemsControlItemTemplate:ItemsControlViewModel x:Key="ItemsControlViewModel" />
	</Grid.Resources>

	<ItemsControl DataContext="{StaticResource ItemsControlViewModel}" ItemsSource="{Binding myItemsSource}">

		<ItemsControl.Style>
			<Style TargetType="ItemsControl">
				<Style.Triggers>

					<DataTrigger Binding="{Binding ParentMyItemType}" Value="{x:Static itemsControlItemTemplate:myItemTypes.WrapPanel}">
						<Setter Property="ItemsPanel">
							<Setter.Value>
								<ItemsPanelTemplate>
									<WrapPanel />
								</ItemsPanelTemplate>
							</Setter.Value>
						</Setter>
					</DataTrigger>

					<DataTrigger Binding="{Binding ParentMyItemType}" Value="{x:Static itemsControlItemTemplate:myItemTypes.StackPanel}">
						<Setter Property="ItemsPanel">
							<Setter.Value>
								<ItemsPanelTemplate>
									<StackPanel />
								</ItemsPanelTemplate>
							</Setter.Value>
						</Setter>
					</DataTrigger>

				</Style.Triggers>
			</Style>
		</ItemsControl.Style>

		<ItemsControl.ItemTemplate>
			<DataTemplate>
			
				<DataTemplate.Resources>
					<itemsControlItemTemplate:AnotherModel x:Key="AnotherModel" />
				</DataTemplate.Resources>

				<Label DataContext="{StaticResource AnotherModel}" Content="{Binding myContent}" />

			</DataTemplate>
		</ItemsControl.ItemTemplate>

	</ItemsControl>

</Grid>

Here notice part, for example:

<DataTrigger Binding="{Binding ParentMyItemType}" Value="{x:Static itemsControlItemTemplate:myItemTypes.WrapPanel}">
	<Setter Property="ItemsPanel">
		<Setter.Value>
			<ItemsPanelTemplate>
				<WrapPanel />
			</ItemsPanelTemplate>
		</Setter.Value>
	</Setter>
</DataTrigger>

Where myItemTypes.WrapPanel I declared something like:

public enum myItemTypes
{
	WrapPanel,
	StackPanel
}

and then my view model looks like:

public class ItemsControlViewModel
{
	public IEnumerable<string> myItemsSource { get; set; }

	public myItemTypes ParentMyItemType { get; set; }

	public ItemsControlViewModel()
	{
		myItemsSource = new[] { "Test1", "Test2" };
		this.ParentMyItemType = myItemTypes.WrapPanel;
	}
}

public class AnotherModel
{
	public string myContent { get; set; }

	public AnotherModel()
	{
		myContent = "test2";
	}
}

notice line:

this.ParentMyItemType = myItemTypes.WrapPanel;

with that line I said that I want my style to be with StackPanel.

Example code you can download from here.