Q:

WPF and C# ComboBox Next Focus

Im using WPF and C#. 
I have an application with an OnScreenKeyboard made with buttons.
When I press the tab button in the OnScreenKeyboard it does this:
if (IsEnterEnabled){
  CurrentTextBox.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
}

CurrentTextBox is a Control.
When a textbox is focused it works fine and move to the next focus, even if the next focus is a comboBox, but if the current focus is in an editable combo box it doesnt move to next focus element.
If the combo box is not editable, it works.

A:

Since the ComboBox has a TextBox inside it which currently has focus,  telling ComboBox to move next will only move to the TextBox.   Instead, get the inner TextBox and move next on that:
        var s1 = FocusManager.GetFocusedElement(this);
        if (s1 is FrameworkElement)
        {
            ((FrameworkElement)s1).MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
        }

