iOS UIViewController 生命周期 APPDelegate 生命周期

释放双眼,带上耳机,听听看~!

UIViewController

1:initialize函数并不会每次创建对象都调用,只有在这个类第一次创建对象时才会调用,做一些类的准备工作,再次创建这个类的对象,initalize方法将不会被调用,对于这个类的子类,如果实现了initialize方法,在这个子类第一次创建对象时会调用自己的initalize方法,之后不会调用,如果没有实现,那么它的父类将替它再次调用一下自己的initialize方法,以后创建也都不会再调用。因此,如果我们有一些和这个相关的全局变量,可以在这里进行初始化。

2:init方法和initCoder方法相似,只是被调用的环境不一样,如果用代码进行初始化,会调用init,从nib文件或者归档进行初始化,会调用initCoder。

3:loadView方法是开始加载视图的起始方法,除非手动调用,否则在ViewController的生命周期中没特殊情况只会被调用一次。

4:viewDidLoad方法是我们最常用的方法的,类中成员对象和变量的初始化我们都会放在这个方法中,在类创建后,无论视图的展现或消失,这个方法也是只会在将要布局时调用一次。

5:viewWillAppear:视图将要展现时会调用。

6:viewWillLayoutSubviews:在viewWillAppear后调用,将要对子视图进行布局。

7:viewDidLayoutSubviews:已经布局完成子视图。

8:viewDidAppare:视图完成显示时调用。

9:viewWillDisappear:视图将要消失时调用。

10:viewDidDisappear:视图已经消失时调用。

11:dealloc:controller被释放时调用。

APPDelegate


#import "AppDelegate.h"

@interface AppDelegate ()

@end

@implementation AppDelegate
            

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    NSLog(@"程序已经启动...");
    return YES;
}

- (void)applicationWillResignActive:(UIApplication *)application {
    NSLog(@"程序将要失去焦点...");
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}

- (void)applicationDidEnterBackground:(UIApplication *)application {
    NSLog(@"程序已经进入后台...");
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

- (void)applicationWillEnterForeground:(UIApplication *)application {
    NSLog(@"程序将要进入前台...");
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}

- (void)applicationDidBecomeActive:(UIApplication *)application {
    NSLog(@"程序已经获得焦点...");
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

- (void)applicationWillTerminate:(UIApplication *)application {
    NSLog(@"程序将要终止...");
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

 

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