Qf--ios Program Operation principle

How iOS Programs work:

The 1> main.m main function is the entry function for all programs.

2> is the Uiapplicationmain function in the main function, which opens an infinite loop to listen to the application.

The Uiapplicationmain function has 4 parameters, the first two are the parameters of the main function, the class name of the 3rd parameter uiapplication, and the 4th is the proxy class name of the application.

2.1> creates an UIApplication instance, one for each application, and one for the entire application.

2.2> creates a UIApplication delegate object, which is the proxy object.

The 3> Appdelegate class is the proxy class for the entire application, which implements the Uiappliactiondelegate protocol, which has several methods for listening to applications.

(delegate events that can be handled include: Application lifecycle events (such as application opening and closing), system events (such as incoming calls), memory warnings, etc.).

Application life cycle method of Appdlegate class and its role

　　

Qf--ios Program Operation principle