应用程序按Home键进入后台时的生命周期

• 进入后台时

  -(void)applicationWillResignActive:(UIApplication *)application;
  -(void)applicationDidEnterBackground:(UIApplication *)application;
  

• 进入前台时

  -(void)applicationDidEnterForeground:(UIApplication *)application;
  -(void)applicationWillResignActive:(UIApplication *)application;