public void NotifyCanExecuteChanged_FiresCanExecuteChangedEvent() { MockCommandHandler<MockArgumentClass> handler = new MockCommandHandler<MockArgumentClass>(); DelegateCommand<MockArgumentClass> command = new DelegateCommand<MockArgumentClass>(handler.Execute, handler.CanExecute); int canExecuteChangedCount = 0; command.CanExecuteChanged += (sender, e) => { canExecuteChangedCount++; }; command.NotifyCanExecuteChanged(); Assert.AreEqual(1, canExecuteChangedCount); }