IOS覆盖本地通知

我创建了一个

本地通知

，当单击某个按钮（

SetButton

）时会触发60秒。我现在的问题是，如果再次按下

SetButton

，它不会覆盖第一次按下，它会显示两个通知，以此类推。我如何确保第二次按下按钮会覆盖第一次按下按钮，并且不会累积通知

- (IBAction)SetButtonPressed:(id)sender {
      UILocalNotification *localNotification = [[UILocalNotification alloc] init];
      localNotification.fireDate = [NSDate dateWithTimeIntervalSinceNow:60];
      localNotification.alertBody = @"HEY GET UP";
      localNotification.timeZone = [NSTimeZone defaultTimeZone];
      localNotification.applicationIconBadgeNumber = [[UIApplication sharedApplication] applicationIconBadgeNumber] + 1;

}

我的

AppDelegate.m

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     UILocalNotification *localNotification = [launchOptions objectForKey:UIApplicationLaunchOptionsLocalNotificationKey];
     if ([UIApplication instanceMethodForSelector: @selector(registerUserNotificationSettings:)]) {
         [application registerUserNotificationSettings: [UIUserNotificationSettings settingsForTypes: UIUserNotificationTypeAlert | UIUserNotificationTypeBadge | UIUserNotificationTypeSound categories:nil]];
     }

     if (localNotification) {
        application.applicationIconBadgeNumber = 0;
     }
}

---

看起来你的应用程序中只有一种类型的本地通知

那样的话，你可以保持简单。每当你想安排一个新的-取消前一个

- (IBAction)SetButtonPressed:(id)sender {
    [[UIApplication sharedApplication] cancelAllLocalNotifications];

    UILocalNotification *localNotification = [[UILocalNotification alloc] init];
    localNotification.fireDate = [NSDate dateWithTimeIntervalSinceNow:60];
    localNotification.alertBody = @"HEY GET UP";
    localNotification.timeZone = [NSTimeZone defaultTimeZone];
    localNotification.applicationIconBadgeNumber = 
      [[UIApplication sharedApplication] applicationIconBadgeNumber] + 1;
}

---

如果您仅对该特定操作使用通知，则可以使用一次取消所有通知

[[UIApplication sharedApplication] cancelAllLocalNotifications];

---

如果你不想让以前的本地通知触发，你必须取消它。或者，如果您不想保留对以前设置的通知的引用，只需取消所有本地通知。请注意，[UILocalNotification]已被弃用…@RokJarc Hi，感谢您的回答，但我如何取消以前的通知。我仍在学习这种情况下最简单的方法是调用

[[UIApplication sharedapplication]cancelAllLocalNotifications]在注册新代码之前。尝试将其作为
设置按钮pressed:
方法的第一行。这样，您就不必保留对以前计划的通知的引用。