TemplateBinding throws an exception when used in a Selector in the ControlTheme

[workgroupengineering]

Describe the bug

XamlX throws Unable to cast object of type 'XamlX.Ast.SkipXamlValueWithManipulationNode' to type 'XamlX.Ast.IXamlAstPropertyReference'.

Stack

10:31:07.792 [Error] 9076 UpdateXamlResult error
System.Xaml.XamlException: Unable to cast object of type 'XamlX.Ast.SkipXamlValueWithManipulationNode' to type 'XamlX.Ast.IXamlAstPropertyReference'.
10:31:31.176 [Information] 9076 Stopping previewer process
10:31:31.177 [Information]  Process exited
10:31:31.177 [Information]  Stopping previewer process
10:32:25.478 [Information]  Started AvaloniaDesigner.CreateCompletionMetadataAsync() for "C:\GitHub\Avalonia\samples\Sandbox\obj\Debug\net6.0\Avalonia\references"
10:32:25.479 [Information]  Starting previewer process for '"C:\GitHub\Avalonia\samples\Sandbox\bin\Debug\net6.0\Sandbox.dll"'
10:32:25.483 [Information] 24432 Started previewer process for '"C:\GitHub\Avalonia\samples\Sandbox\bin\Debug\net6.0\Sandbox.dll"'. Waiting for connection to be initialized.
10:32:25.926 [Information] 24432 Connection initialized
10:32:27.424 [Error] 24432 UpdateXamlResult error
System.Xaml.XamlException: Unable to cast object of type 'XamlX.Ast.SkipXamlValueWithManipulationNode' to type 'XamlX.Ast.IXamlAstPropertyReference'.

To Reproduce

Steps to reproduce the behavior:

Add folowing xaml

  <ControlTheme x:Key="{x:Type NumericUpDown}"
                TargetType="NumericUpDown">
        ....
        <Style Selector="^[ButtonSpinnerLocation=Left] /template/ TextBox#PART_TextBox">
          <Setter Property="InnerRightContent" Value="{TemplateBinding InnerContent}"/>
        </Style>

        <Style Selector="^[ButtonSpinnerLocation=Right] /template/ TextBox#PART_TextBox">
          <Setter Property="InnerLeftContent" Value="{TemplateBinding InnerContent}"/>
        </Style>
  </ControlTheme>

Expected behavior

A clear and concise description of what you expected to happen.

Screenshots

If applicable, add screenshots to help explain your problem.

Environment

• OS: Any
• Avalonia-Version: ffff19e

Additional context

if change like this works:

  <ControlTheme x:Key="{x:Type NumericUpDown}"
                TargetType="NumericUpDown">
        ....
    <Style Selector="^[ButtonSpinnerLocation=Left] /template/ TextBox#PART_TextBox">
      <Setter Property="InnerRightContent" Value="{Binding InnerContent, RelativeSource={RelativeSource TemplatedParent}}"/>
    </Style>

    <Style Selector="^[ButtonSpinnerLocation=Right] /template/ TextBox#PART_TextBox">
      <Setter Property="InnerLeftContent" Value="{Binding InnerContent, RelativeSource={RelativeSource TemplatedParent}}"/>
    </Style>
  </ControlTheme>

[timunie]

TemplateBinding is more limited than Binding for performance reasons. I believe this is by design and if it's not enough, you need to fall back to a normal Binding (like you did already). Note, you are outside ControlTemplate here. I agree that the error message could be improved.

[maxkatz6]

There should be another warning or an error before this one.

[maxkatz6]

I also can't reproduce this issue by adding InnerContent property and these setters.

[workgroupengineering]

TemplateBinding is more limited than Binding for performance reasons. I believe this is by design and if it's not enough, you need to fall back to a normal Binding (like you did already). Note, you are outside ControlTemplate here. I agree that the error message could be improved.

Then this shouldn't have worked either {Binding InnerContent, RelativeSource={RelativeSource TemplatedParent}} but only

{Binding InnerContent, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type NumericUpDown}}}

I also can't reproduce this issue by adding InnerContent property and these setters.

I attach a modified SandBox that simulates the problem

Sandbox.zip