Master/Detail——如果对象被删除，或者在Master (iOS)中没有对象，则要清晰的细节

In my iPad app (or iPhone 6 Plus in landscape) I am using a master/detail UISplitViewController. When the user deletes the currently selected item from the Master or deletes all the items from the Master, the previously selected item's detail remains in the Detail view.In my iPad app (or iPhone 6 Plus in landscape)