Controller logic Jump Push POP

Recently developed a new project, is a shopping mall type of project, which is my responsibility for the details of the interface, there is nothing to say, the right side of the NavBarItem to jump to the front page of the options, I abused the dead, and colleagues in the addition of a relay controller, just started completely confused, and then slowly clear.

First of all, the push and pop, these two methods is the operation of a stack, push is to the stack inside the controller, Pop is out of the stack, the controller pops up, in the stack to do the top-level controller is displayed on the interface. If you don't have a controller in your stack, you don't want pop to a. A pop requires an operation between the controllers in the same stack.

The push controller presses the controller into the stack, and one object cannot be pressed into the second. A Class A AA object can be pressed into the AB object. When the controller is located in the stack with ABCDEFGF controller is, from the G controller can pop to the A-f controller, if you want to pop to the F controller is not possible, only pop to the bottom of its own controller, similarly, not in the G object stack of H controller also can not be pop to

Controller logic Jump Push POP