请求用户允许在 iOS 8 中接收 UILocalNotifications

我已经在应用程序委托中使用以下命令设置了本地通知：

- (void)applicationDidEnterBackground:(UIApplication *)application
{
    UILocalNotification *notification = [[UILocalNotification alloc]init];
    [notification setAlertBody:@"Watch the Latest Episode of CCA-TV"];
    [notification setFireDate:[NSDate dateWithTimeIntervalSinceNow:5]];
    [notification setTimeZone:[NSTimeZone defaultTimeZone]];
    [application setScheduledLocalNotifications:[NSArray arrayWithObject:notification]];
}

当我运行该应用程序然后退出它时，我收到一条错误消息：

2014-06-07 11:14:16.663 CCA-TV[735:149070]尝试安排本地通知{火 日期 = 2014 年 6 月 7 日星期六 11:14:21 太平洋夏令时间，时间 区域 = America/Los_Angeles (PDT) 偏移量 -25200（日光），重复 间隔 = 0，重复计数 = UILocalNotificationInfiniteRepeatCount， 下次火灾日期 = 2014 年 6 月 7 日星期六 11:14:21 太平洋夏令时 时间、用户信息 = (null)}有警报但尚未收到 用户允许显示警报

我如何获得显示警报所需的权限？

从 iOS 8 开始，您需要征得用户的许可才能显示应用程序的通知，这适用于远程/推送和本地通知。在 Swift 中你可以这样做，

Swift 2.0 更新

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: NSDictionary?) -> Bool {
    // Override point for customization after application launch.
    if(UIApplication.instancesRespondToSelector(Selector("registerUserNotificationSettings:")))
    {
        let notificationCategory:UIMutableUserNotificationCategory = UIMutableUserNotificationCategory()
        notificationCategory.identifier = "INVITE_CATEGORY"
        notificationCategory.setActions([replyAction], forContext: UIUserNotificationActionContext.Default)

        //registerting for the notification.
        application.registerUserNotificationSettings(UIUserNotificationSettings(forTypes:[.Sound, .Alert, .Badge], categories: nil))
    }
    else
    {
       //do iOS 7 stuff, which is pretty much nothing for local notifications.
    }
    return true
}

斯威夫特 3.2

if(UIApplication.instancesRespond(to: #selector(UIApplication.registerUserNotificationSettings(_:)))){
     let notificationCategory:UIMutableUserNotificationCategory = UIMutableUserNotificationCategory()
     notificationCategory.identifier = "INVITE_CATEGORY"
     notificationCategory.setActions([replyAction], forContext: UIUserNotificationActionContext.Default)

     //registerting for the notification.
        application.registerUserNotificationSettings(UIUserNotificationSettings(types:[.sound, .alert, .badge], categories: nil))
}
else{
        //do iOS 7 stuff, which is pretty much nothing for local notifications.
    }

Objective C 语法也非常相似。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    if ([UIApplication instancesRespondToSelector:@selector(registerUserNotificationSettings:)]){
        [application registerUserNotificationSettings:[UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert|UIUserNotificationTypeBadge|UIUserNotificationTypeSound categories:nil]];
    }
    // Override point for customization after application launch.
    return YES;
}

要检查当前注册的通知类型，您可以使用 UIApplication 类的方法，

- (UIUserNotificationSettings *)currentUserNotificationSettings

因此，如果用户对您的应用程序说“不”，那么此函数应该返回一个不带任何类型的设置。

我写了一篇关于这个的教程，你可以看看here http://thecodeninja.tumblr.com/post/89942124085/notifications-in-ios-8-part-1-using-swift-what-is.