Issue with DependencyProperty binding

Question

I created a small File Browser Control:

Answer 1

The primary problem is that you set your UserControl's DataContext to itself in its constructor:

DataContext = this;

You should not do that, because it breaks any DataContext based Bindings, e.g. to a view model instance in the inherited DataContext value.

Instead you would change the binding in the UserControl's XAML like this:

Now, when you use your UserControl and write a binding like

the SelectedFile property gets bound to a SelectedFile property in your view model, which should be in the DataContext inherited from a parent control.