Public Class DialogController
The DialogController class is a descendant of the WindowController class. It is intended to present the Accept and Cancel buttons in pop-up Windows. You can inherit from this Controller to modify its behavior.
The Dialog Controller has a peculiarity. It is not added to a Frame's Frame.Controllers collection automatically. You should add it yourself.
Basically, the Dialog Controller is required in pop-up Windows only. There are two approaches to add a Dialog Controller to a pop-up Window: