帮助更改textLabel的NSTimer。代码包括在内

问题描述

想要将我的NSTimer代码更改为使用applicationSignificantTimeChange

want to change my NSTimer code to to use applicationSignificantTimeChange

这就是我现在所拥有的。

This is what I have right now.

基本上我想更改计时器，而不是每5秒更换一次，例如我希望这些textLabels每天晚上12点更改，有人帮我解决？

Basically I want to change the timer, instead of changing every 5 seconds for example I want these textLabels to change at 12am every night anyone help me out?

//h file

NSTimer *timer;

IBOutlet UILabel *textLabel;

//m file

- (void)onTimer {

    static int i = 0;

    if ( i == 0 ) {
        textLabel.text = @"iphone app";
    }

    else if ( i == 1 ) {
        textLabel.text = @" Great App!";
    }

    else if ( i == 2 ) {
        textLabel.text = @" WOW!";
    }

    else {
        textLabel.text = @" great application again!!";
        i = -1;
    }

    i++;
}


timer =[NSTimer scheduledTimerWithTimeInterval:5.0 target:self selector:@selector(onTimer) userInfo:nil repeats:YES];

推荐答案

你可以做两件事来回应applicationSignificantTimeChange：

There are two things you can do to respond to a applicationSignificantTimeChange:

（1）如果你有一个应该更新的视图控制器的连接，只需在app delegate中实现applicationSignificantTimeChange：

(1) Just implement applicationSignificantTimeChange: in your app delegate if you have a connection to the view controller that should be updated.

- (void)applicationSignificantTimeChange:(UIApplication *)application {
  yourViewController.textLabel.text = @"random text";
}

（2）在视图控制器中订阅应该获得的UIApplicationSignificantTimeChangeNotification通知更新。您可以将该代码放入viewDidLoad

(2) Subscribe to the UIApplicationSignificantTimeChangeNotification notification in the view controller that should get the update. You could perhaps put that code in viewDidLoad

- (void)viewDidLoad {
    [super viewDidLoad];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(onSignificantTimeChange:)
                                                 name:UIApplicationSignificantTimeChangeNotification
                                               object:nil];
}

- (void)onSignificantTimeChange:(NSNotification *)notification {
    self.textLabel.text = @"random text";
}

您还需要致电

[[NSNotificationCenter defaultCenter] removeObserver:self];

当您的视图控制器不再需要时。

somewhere when your view controller is not longer needed.

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