I intended to disable and enable the Buttons outside the TabControl, just like those inside the TabItem when the current tab is changed. But the CommandBindings of the TabIt
Your don't have any code that could disable buttons. You can do it in several ways:
1. Define CanExecute event handler.
Code behind:
private void MyCommand_CanExecute(object sender, CanExecuteRoutedEventArgs e)
{
e.CanExecute = tabItem1.IsSelected;
}
2. Bind button IsEnabled property to tab item IsSelected property