TemplatedControl

TemplateControl is Style

The xaml part of TemplatedControl is essentially a predefined styles targeted to the code-behind type. TemplatedControl.Template is of IControlTemplate, which is typically typed as ControlTemplate. The xaml representation of TemplatedControl is a ControlTheme(a sibling type of Style) stored in ResourceDictionary. Its value would be loaded by styling system, as what was defined in xaml part.

public class TemplatedControl : Control {
    /** ... **/
    public static readonly StyledProperty<IControlTemplate?> TemplateProperty =
        AvaloniaProperty.Register<TemplatedControl, IControlTemplate?>(nameof(Template));

    public IControlTemplate? Template {
        get => GetValue(TemplateProperty);
        set => SetValue(TemplateProperty, value);
    }
    /** ... **/
}

<ResourceDictionary
  xmlns="https://github.com/avaloniaui"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:controls="using:MyAva.Views">

  <Design.PreviewWith>
    <StackPanel Width="400" Spacing="10">
      <StackPanel Background="{DynamicResource SystemRegionBrush}">
        <controls:MyTemplatedControl />
        <controls:MyTemplatedControl />
      </StackPanel>
    </StackPanel>
  </Design.PreviewWith>

  <ControlTheme x:Key="{x:Type controls:MyTemplatedControl}" TargetType="controls:MyTemplatedControl">
    <Setter Property="Template">
      <ControlTemplate> 
        <TextBlock Text="Templated Control" /> 
      </ControlTemplate> 
    </Setter>
  </ControlTheme>
</ResourceDictionary>

NOTE

Before Avalonia 0.11.0, TemplatedControl was structured as Styles.

older TemplatedControl presentation

<Styles xmlns="https://github.com/avaloniaui"
       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
       xmlns:controls="using:MyAva.Views">
   <Design.PreviewWith>
       <controls:MyTemplatedControl />
   </Design.PreviewWith>

   <Style Selector="controls|MyTemplatedControl"> 
       <!-- Set Defaults -->
       <Setter Property="Template">
           <ControlTemplate>
               <TextBlock Text="Templated Control" />
           </ControlTemplate>
       </Setter>
   </Style>
</Styles>