The complete process of app startup

The complete process of app startup

1. When the program starts, the Main method in main. m will be called first.

2. Call the UIApplicationMain method.

UIApplicationMain (argc, argv, @ "Application class name, must be UIApplication (or subclass). If it is nil, the default value is UIApplication", @ "Application proxy class ");

2.1 create a UIApplication object

2.2 create a delegate object for UIApplication

(No storyboard)

3. The delegate object starts to process (Listen) system events.

3.1 create a UIWindow in application: didfinishlaunchingwitexceptions:

3.2 Create and set the rootViewController of UIWindow

3.3 display window

(With storyboard)

3. Obtain the file name of the primary storyboard Based on Info. plist and load the primary storyboard.

3.1 create a UIWindow

3.2 Create and set the rootViewController of UIWindow

3.3 display window