调用enabledremotenotificationsttypes并检查掩码。

例如:

UIRemoteNotificationType types = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
if (types == UIRemoteNotificationTypeNone) 
   // blah blah blah

iOS8及以上:

[[UIApplication sharedApplication] isRegisteredForRemoteNotifications]

下面是如何在Xamarin.ios中做到这一点。

public class NotificationUtils
{
    public static bool AreNotificationsEnabled ()
    {
        var settings = UIApplication.SharedApplication.CurrentUserNotificationSettings;
        var types = settings.Types;
        return types != UIUserNotificationType.None;
    }
}

如果你支持iOS 10+，只使用UNUserNotificationCenter方法。

在iOS7和之前，你应该使用enabledRemoteNotificationTypes并检查它是否等于(或不等于取决于你想要什么)UIRemoteNotificationTypeNone。

然而，对于iOS8来说，仅仅检查isregisteredforremotenotifations并不总是足够的，因为上面有许多状态。你还应该检查application.currentUserNotificationSettings.types是否等于(或不等于取决于你想要什么)UIUserNotificationTypeNone!

isregisteredforremotenotifations可能返回true，即使currentUserNotificationSettings。types返回UIUserNotificationTypeNone。

iOS8+ (OBJECTIVE C)

#import <UserNotifications/UserNotifications.h>


[[UNUserNotificationCenter currentNotificationCenter]getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {

    switch (settings.authorizationStatus) {
          case UNAuthorizationStatusNotDetermined:{

            break;
        }
        case UNAuthorizationStatusDenied:{

            break;
        }
        case UNAuthorizationStatusAuthorized:{

            break;
        }
        default:
            break;
    }
}];

UIRemoteNotificationType types = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
if (types & UIRemoteNotificationTypeAlert)
    // blah blah blah
{
    NSLog(@"Notification Enabled");
}
else
{
    NSLog(@"Notification not enabled");
}

这里我们从UIApplication获得UIRemoteNotificationType。它代表了这个应用程序在设置中的推送通知的状态，然后你可以很容易地检查它的类型

swift4.0, iOS11的更新代码

import UserNotifications

UNUserNotificationCenter.current().getNotificationSettings { (settings) in
   print("Notification settings: \(settings)")
   guard settings.authorizationStatus == .authorized else { return }

   //Not authorised 
   UIApplication.shared.registerForRemoteNotifications()
}

swift3.0, iOS10的代码

    let isRegisteredForRemoteNotifications = UIApplication.shared.isRegisteredForRemoteNotifications
    if isRegisteredForRemoteNotifications {
        // User is registered for notification
    } else {
        // Show alert user is not registered for notification
    }

从iOS9开始，swift 2.0的UIRemoteNotificationType已弃用，请使用以下代码

let notificationType = UIApplication.shared.currentUserNotificationSettings!.types
if notificationType == UIUserNotificationType.none {
        // Push notifications are disabled in setting by user.
    }else{
  // Push notifications are enabled in setting by user.

}

只需检查是否启用了推送通知

    if notificationType == UIUserNotificationType.badge {
        // the application may badge its icon upon a notification being received
    }
    if notificationType == UIUserNotificationType.sound {
        // the application may play a sound upon a notification being received

    }
    if notificationType == UIUserNotificationType.alert {
        // the application may display an alert upon a notification being received
    }