Commit Focused Element in Silverlight

I need code that will force Silverlight to commit the focused element (in my case a TextBox, but it could be anything). In WPF I use

public static void CommitFocusedElement() {
    UIElement element = Keyboard.FocusedElement as UIElement;
    if (element != null) {
        TraversalRequest request = new TraversalRequest(FocusNavigationDirection.Next);
        FocusNavigationDirection directionBack = FocusNavigationD开发者_C百科irection.Previous;
        if (!element.MoveFocus(request)) {                    
            request = new TraversalRequest(FocusNavigationDirection.Previous);
            directionBack = FocusNavigationDirection.Next;
            element.MoveFocus(request);
        }
        if (element.Focusable)
        {
            element.Focus();
        }
        else
        {
            element.MoveFocus(new TraversalRequest(directionBack));
        }
    }
}

But several parts of this code is not Silverlight compatible. Can anyone point me to a Silverlight alternative?

I'm assuming you want to update the source of a binding. If you're not, you probably should.

BindingExpression expression = textBox1.GetBindingExpression(TextBox.TextProperty);
expression.UpdateSource();