Solving the getview of region in Prism does not work.

In general, when adding a view to a region, we need to determine if the view already exists in region, but if we are not at the time of the Region.add method call, we always return null in GetView because of an error in Add

Error review

view = ServiceLocator.Current.GetInstance (typeof (Applicationview), "Applicationview");

This. Regionmanager.regions[regionnames.maincontentregion]. ADD (view);

In this way we

var view=this. Regionmanager.regions[regionnames.maincontentregion]. GetView ("Applicationview");

The returned result will always be null, and the correct calling method is shown below

var view=this. Regionmanager.regions[regionnames.maincontentregion].            GetView ("Applicationview"); if (view = = null) {view = ServiceLocator.Current.GetInstance (typeof (Applicationview), "Applicat                Ionview "); This. Regionmanager.regions[regionnames.maincontentregion].            ADD (View, "Applicationview"); } this. Regionmanager.regions[regionnames.maincontentregion]. Activate (view);

Solving the getview of region in Prism does not work.