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  • ios 监听app从后台恢复到前台

    正常情况下,在AppDelegate中实现下面两个方法,能够监听从后台恢复到前台


    [cpp] 
    - (void)applicationDidEnterBackground:(UIApplication *)application 

        log4info(@"---applicationDidEnterBackground----"); 
       //进入后台  

     
    - (void)applicationDidBecomeActive:(UIApplication *)application 

     
        NSLog(@"---applicationDidBecomeActive----"); 
        //进入前台  
     
         

    - (void)applicationDidEnterBackground:(UIApplication *)application
    {
        log4info(@"---applicationDidEnterBackground----");
       //进入后台
    }

    - (void)applicationDidBecomeActive:(UIApplication *)application
    {

        NSLog(@"---applicationDidBecomeActive----");
        //进入前台

       
    }


    但是单个UIViewController怎么监听呢

    在-viewDidLoad方法中,添加一下代码监听notification


    [cpp]
    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(someMethod:) 
                                                 name:UIApplicationDidBecomeActiveNotification object:nil]; 

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(someMethod:)
                                                 name:UIApplicationDidBecomeActiveNotification object:nil];
    别忘了在-dealloc中将监听移除:


    [cpp] 
    [[NSNotificationCenter defaultCenter] removeObserver:self]; 

    [[NSNotificationCenter defaultCenter] removeObserver:self];

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  • 原文地址:https://www.cnblogs.com/wanghuaijun/p/5659907.html
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