如何使用UIApplicationDidBecomeActiveNotification

Question

怎么用UIApplicationDidBecomeActiveNotification？

我应该在从后台到前台进行声明viewDidLoad或viewWillAppear重新加载数据.

不UIApplicationDidBecomeActiveNotification被调用,只有当应用程序来自于背景,前景？

请帮忙.谢谢.

Answer 1

有时,当你需要在视图控制器中从后台唤醒时(如果你在屏幕上使用此视图控制器进入后台),有一个UIApplicationDidBecomeActiveNotification的监听器是有用的.在这样的唤醒视图中,WillAppear不会被触发!

使用示例:

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

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


- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationDidBecomeActiveNotification object:nil];

}

- (void)someMethod
{
    <YOUR CODE AT WAKE UP FROM BACKGROUND>
}

当然,您也可以在app delegate类生命周期中实现所需的一切.