Using a TemplateBinding in ControlTemplate.Triggers

Question

Why does the following piece of XAML give me a XamlParseException with the (meaningless) message \"Expression type is not a valid Style value.\" at runtime?

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Answer 1

Triggers work best when defined in stand-alone styles, not in-place content. Try defining your trigger in a style resource, then reference the style resource from your template.

Answer 2

Binding TemplatedParent: In this line the value of the path2 is going to apply for the Text property of the TextBlock, so it runs fine.

In TemplateBinding : Have a close look at this, The resolved value of the Max:MyControl.Bar is going to act as the resource key for the Template binding [Here the value of Bar is not an actual value, instead it s a property key name ] which doesnt exists and so it throws the error "The given key was not present in the dictionary."