iOS 在viewController中监听Home键触发以及重新进入界面的方法

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillResignActive:)
name:UIApplicationWillResignActiveNotification object:nil]; //监听是否触发home键挂起程序.
    
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationDidBecomeActive:)
name:UIApplicationDidBecomeActiveNotification object:nil]; //监听是否重新进入程序程序.

- (void)applicationWillResignActive:(NSNotification *)notification

{
    printf("按理说是触发home按下\n");
}

- (void)applicationDidBecomeActive:(NSNotification *)notification
{
    printf("按理说是重新进来后响应\n");
}

- (void)applicationDidEnterBackground:(UIApplication *)application
{
/*
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.
*/
}