public static object AddControl(this UserControl userControl, object control, object parent = null,
SelectionChangedEventHandler selectionChanged = null, object[] controls = null)
{
var content = parent ?? userControl.Content;
if (content == null || content is Grid)
{
return(userControl.AddTabControl(control as UIElement, selectionChanged));
}
if (content is TabControl)
{
return(userControl.AddTabItem(control as UIElement, content as TabControl, controls));
}
return(control);
}