WPF TreeView restores its focus after double click

Question

I have a WPF TreeView with XAML shown below:

Answer 1

You probably need to let WPF finish the job of handling the current mouse click event(s) before you open the new Window. Let the new window be the next UI job by adding it to the current Dispatcher's queue like this:

(...)

//Editor.Show();
Action showAction = () => Editor.Show();
this.Dispatcher.BeginInvoke(showAction);