Ios-appdelegate life cycle

-(void) Applicationwillresignactive: (uiapplication *) application

Description: When the application is going to be inactive, during which time the application does not receive messages or events, such as coming to the phone

-(void) Applicationdidbecomeactive: (uiapplication *) application

Description: When the application executes in the active state, this is exactly the opposite of the method above

-(void) Applicationdidenterbackground: (uiapplication *) application

Description: Called when the program is pushed to the background. So to set the background to continue running, you can set it in this function

-(void) Applicationwillenterforeground: (uiapplication *) application

Description: Called when the program is going back to the foreground from the background, which is exactly the opposite of the method above.

-(void) Applicationwillterminate: (uiapplication *) application

Description: When the program is about to exit is called, it is usually used to save the data and some cleanup work before exiting. This needs to set the key value of the uiapplicationexitsonsuspend.

-(void) applicationdidreceivememorywarning: (uiapplication *) application

Description: The iphone device has only limited memory, and if the application is assigned too much memory the operating system will terminate the application's operation, this method will be executed before termination, usually can be done in the memory cleanup work to prevent the program from being terminated

-(void) Applicationsignificanttimechange: (uiapplication*) application

Description: Executes when the system time has changed

-(void) applicationdidfinishlaunching: (uiapplication*) application

Description: Executes when the program is loaded

-(void) application: (uiapplication) Application Willchangestatusbarframe: (cgrect) Newstatusbarframe

Description: Executes when the StatusBar box is going to change

-(void) application: (uiapplication*) Application willchangestatusbarorientation:

1. (uiinterfaceorientation) newstatusbarorientation
2. Duration: (nstimeinterval) duration

Description: Executed when the StatusBar box direction is going to change

-(BOOL) Application: (uiapplication*) Application Handleopenurl: (nsurl*) URL

Description: When executing via URL

-(void) application: (uiapplication*) Application didchangestatusbarorientation: (uiinterfaceorientation) Oldstatusbarorientation

Description: Executes when the StatusBar box direction changes

-(void) application: (uiapplication*) Application Didchangesetstatusbarframe: (cgrect) Oldstatusbarframe

Description: Executes when the StatusBar box changes

I summed up a approximate flowchart, not very accurate but basically also explains the whole process, for reference only.

Ios-appdelegate life cycle