监听APP进入前台与后台

在其它页面监听APP进入后台与前台

- (void)viewDidLoad {
    [super viewDidLoad];
     // 监听APP进入后台
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(detectAppEnterBackground) name:UIApplicationDidEnterBackgroundNotification object:nil];
    // 监听APP进入前台
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(detectAppEnterForeground) name:UIApplicationWillEnterForegroundNotification object:nil];

}

// 进入后台 - 监听方法
- (void)detectAppEnterBackground
{
    NSLog(@"%s", __func__);
}
// 进入前台 - 监听方法
- (void)detectAppEnterForeground
{
    NSLog(@"%s", __func__);
}