WPF MVVM取消Window.Closing事件

In WPF application together with MVVMLight Toolkit, I would like to see your opinion, what is the best way to implement if I need to Cancel the Window Close event. In Window.Closing event I can set the e.Cancel = true, which prevents closing the form. To identify if the Close is allowed, or should be prevented is in the ViewModel context.In WPF application together with MVVMLight Tool