Binding causes StackOverflow

Question

Im not sure what I am doing wrong here.

Lets say, I have two UserControls BoxAand BoxB. Both have a DependencyProperty called Text

Answer 1

If you are building a UserControl with bindable properties (i.e. dependency properties), you must under no circumstances explicitly set the UserControl's DataContext, be it to the control instance or to any private view model.

If you do that, a Binding like

will no longer work. That Binding expects a Title property in the object in the current DataContext. The DataContext property value is usually inherited from the parent element of the UserControl, e.g. the Window. However, since you've explicitly set the DataContext, this mechanism is avoided.

This becomes particularly confusing with equally named properties in UserControls. When you write

in UserControl BoxB, your expectation is that the Binding source property is BoxB.Text. In fact it is BoxA.Text, because BoxA's DataContext is the BoxA instance.

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So remove any

DataContext="{Binding RelativeSource={RelativeSource Self}}"

lines and write the Bindings in the UserControl's XAML with RelativeSource like this: