AvaloniaUI/Avalonia · error · InvalidOperationException

Cannot find a StyledElement to get a TemplatedParent.

Error message

Cannot find a StyledElement to get a TemplatedParent.

What it means

TemplatedParentNode.SelectSource throws InvalidOperationException when neither target nor anchor is a StyledElement. TemplatedParent is a StyledElement property, so a non-StyledElement target cannot supply it.

Source

Thrown at src/Avalonia.Base/Data/Core/ExpressionNodes/TemplatedParentNode.cs:22

namespace Avalonia.Data.Core.ExpressionNodes;

internal sealed class TemplatedParentNode : SourceNode
{
    public override void BuildString(StringBuilder builder)
    {         
        builder.Append("$templatedParent");
    }

    public override object? SelectSource(object? source, object target, object? anchor)
    {
        if (source != AvaloniaProperty.UnsetValue)
            throw new NotSupportedException(
                "TemplatedParentNode is invalid in conjunction with a binding source.");
        if (target is StyledElement)
            return target;
        if (anchor is StyledElement)
            return anchor;
        throw new InvalidOperationException("Cannot find a StyledElement to get a TemplatedParent.");
    }

    protected override void OnSourceChanged(object? source, Exception? dataValidationError)
    {
        if (!ValidateNonNullSource(source))
            return;

        if (source is StyledElement newElement)
        {
            newElement.PropertyChanged += OnPropertyChanged;
            SetValue(newElement.TemplatedParent);
        }
        else
        {
            SetError($"Unable to read TemplatedParent from '{source.GetType()}'.");
        }
    }

View on GitHub (pinned to 11c5427268)

Solutions

1. Use $templatedParent only inside a ControlTemplate applied to a StyledElement.
2. Outside templates, bind to the real source object or use a different RelativeSource ($self, $parent).

Example fix

// before - outside a template
<TextBlock Text="{Binding $templatedParent.Title}" />
// after - inside the ControlTemplate of a templated control
<ControlTemplate><TextBlock Text="{Binding $templatedParent.Title}" /></ControlTemplate>

// TemplatedParent requires a StyledElement target.
if (target is not StyledElement)
    throw new InvalidOperationException("Target is not a StyledElement; cannot resolve TemplatedParent.");

static bool CanResolveTemplatedParent(object o) => o is StyledElement;

try { target.Bind(prop, binding); }
catch (InvalidOperationException ex) when (ex.Message.Contains("StyledElement"))
{ /* use a non-template binding or a different relative source */ }

When it happens

Trigger: Using a $templatedParent binding outside a ControlTemplate (no templated parent exists), or on an object that is not a StyledElement.

Common situations: Using $templatedParent in a normal (non-template) binding; applying a templated-parent binding to a raw Visual or non-styled element; a control that has no template applied.

Related errors

• TemplatedParentNode is invalid in conjunction with a binding
• DataContextNode is invalid in conjunction with a binding sou
• LogicalAncestorNode is invalid in conjunction with a binding
• Cannot find an ILogical to get a logical ancestor.
• Cannot find an ILogical to get a visual ancestor.

AI-assisted analysis of AvaloniaUI/Avalonia@11c5427268 (2026-08-13). Data as JSON: /api/errors/2128c8e524dd6c21. Report an issue: GitHub.