Occurs before setting the View.Model property for a View.
The ModelChanging event's data class is EventArgs.
This event occurs as a result of calling the current View's View.SetModel method. This method is called to set or change a value for the View's View.Model property. After this property's value is changed, the View's settings will be updated and its controls will be created (recreated). Handle this event to perform custom actions before changing the View.Model property's value.