ios - UIApplicationDidBecomeActiveNotification 过滤通知

Question

我注册了我的主视图控制器以进行收听，UIApplicationDidBecomeActiveNotification因为我想在UIAlertView每次用户进入我的应用程序时显示一个：

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

它就像一个魅力，我唯一的问题是如果我的应用程序被中断（UIAletView例如日历事件或要求图片访问确认的弹出窗口），一旦警报视图被关闭，通知就会被调用。

关于如何仅在我的应用程序从后台模式返回时进行检测的任何想法？

Answer 1

你为什么不使用AppDelegate方法，

- (void)applicationWillEnterForeground:(UIApplication *)application
{
 //do whatever you want when app comes from background to foreground
}

Answer 2

我知道这是一个旧线程，但有一个 UIApplicationWillEnterForegroundNotification。像这样工作：

  [[NSNotificationCenter defaultCenter]addObserver:self
                                selector:@selector(myMethod)
                                    name:UIApplicationWillEnterForegroundNotification
                                        object:nil];

此致，

加百列富冢

Answer 3

Check state (active/background) of your application by following code:

UIApplicationState state = [[UIApplication sharedApplication] applicationState];
if (state == UIApplicationStateActive)
{

        /// your stuff of code:
}

Above code might be useful in your case: