Can't set focus to a child of UserControl

Question

I have a UserControl which contains a TextBox. When my main window loads I want to set the focus to this textbox so I added Focusable=\"True

Answer 1

What did the trick for me was the FocusManager.FocusedElement attribute. I first tried to set it on the UserControl, but it didn't work.

So I tried putting it on the UserControl's first child instead:

... and it worked! :)