Keybord focus can be set by pessing Tab keyboard key. But is is not set when click on the control. I've subscribed to the MouseDown event and set focus manually in the handler.
public class FocusTestControl : Control, IInputElement {
public FocusTestControl() {
DefaultStyleKey = typeof(FocusTestControl);
MouseDown += FocusTestControl_MouseDown;
}
void FocusTestControl_MouseDown(object sender, System.Windows.Input.MouseButtonEventArgs e) {
Keyboard.Focus(this);
}
}