One controller, nested inside another controller.

1, in the parent controller, the introduction of the sub-Controller header file

2.

Cztwoviewcontroller *two = [[Cztwoviewcontroller alloc] init];

[self addchildviewcontroller: both];

3. In the parent controller, you can use the method of the child controller.

Role: 1, when a function has been written, but also in the implementation of another controller, nested.

2, let all functions in the development, relatively independent.

One controller, nested inside another controller.