在WPF中，是否有视图模型需要调用视图w.r.t. MVVM上的方法?

As per the pattern, the ViewModel exposes Properties(with change notification) and Commands (to notify the VM of user actions) that the View binds to. The only communication that flows from the VM to the View is the property change notifications (so that the View can refresh itself with updated data). As per the pattern, the ViewModel exposes Prope