In WPF, why doesn't TemplateBinding work where Binding does?

Question

Ok... this is leaving me scratching my head. I have two WPF controls--one\'s a user control and the other\'s a custom control. Let\'s call them UserFoo and CustomFoo. In

Answer 1

TemplateBinding does not support two-way binding, only Binding does that. Even with your BindsTwoWayBeDefault option, it won't support two-way binding.

More info can be found here, but to summarize:

However, a TemplateBinding can only transfer data in one direction: from the templated parent to the element with the TemplateBinding. If you need to transfer data in the opposite direction or both ways, a Binding with RelativeSource of TemplatedParent is your only option. For example, interaction with a TextBox or Slider within a template will only change a property on the templated parent if you use a two-way Binding.