Vista - Commandbindings of UIelement

hi, I have another question about command. I define a custom command
and bind it to menuitem.
the code as follows:
public partial class MenuToolBarTestCase : Page
{
public static readonly RoutedCommand testcommand;
public MenuToolBarTestCase()
{
InitializeComponent();
Loaded += new
RoutedEventHandler(MenuToolBarTestCase_Loaded);
}
static MenuToolBarTestCase()
{
testcommand= new RoutedCommand("testcommand",
typeof(MenuToolBarTestCase));
testcommand.InputGestures.Add(new KeyGesture(Key.C,
ModifierKeys.Alt));
}
void MenuToolBarTestCase_Loaded(object sender, RoutedEventArgs
e)
{
XMenuItem.Command = testcommand; //(If I remove it,
command won't be executed)
CommandBinding CB = new CommandBinding(tt);
CB.CanExecute += new
CanExecuteRoutedEventHandler(CB_CanExecute);
CB.Executed += new ExecutedRoutedEventHandler(CB_Executed);
XMenuItem.CommandBindings.Add(CB);
}
void CB_Executed(object sender, ExecutedRoutedEventArgs e)
{
}
void CB_CanExecute(object sender, CanExecuteRoutedEventArgs e)
{
e.CanExecute = true;
}

if I remove "XMenuItem.Command = testcommand" , testcommand won't be
enable and executed. Does it mean that a control execute attahced
command only?
Virtual

the problem is solved. it's focus issue.