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]

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
    }

在尝试同时支持iOS8和更低版本时，我并没有像Kevin建议的那样使用isregisteredforremotenotifations。相反，我使用了currentUserNotificationSettings，它在我的测试中工作得很好。

+ (BOOL)notificationServicesEnabled {
    BOOL isEnabled = NO;

    if ([[UIApplication sharedApplication] respondsToSelector:@selector(currentUserNotificationSettings)]){
        UIUserNotificationSettings *notificationSettings = [[UIApplication sharedApplication] currentUserNotificationSettings];

        if (!notificationSettings || (notificationSettings.types == UIUserNotificationTypeNone)) {
            isEnabled = NO;
        } else {
            isEnabled = YES;
        }
    } else {
        UIRemoteNotificationType types = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
        if (types & UIRemoteNotificationTypeAlert) {
            isEnabled = YES;
        } else{
            isEnabled = NO;
        }
    }

    return isEnabled;
}

完全容易复制和粘贴代码构建从@ZacBowling的解决方案(https://stackoverflow.com/a/1535427/2298002)

这也将把用户带到你的应用程序设置，并允许他们立即启用

我还添加了一个解决方案，用于检查位置服务是否启用(以及带来的设置)

// check if notification service is enabled
+ (void)checkNotificationServicesEnabled
{
    if (![[UIApplication sharedApplication] isRegisteredForRemoteNotifications])
    {
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Notification Services Disabled!"
                                                            message:@"Yo don't mess around bro! Enabling your Notifications allows you to receive important updates"
                                                           delegate:self
                                                  cancelButtonTitle:@"Cancel"
                                                  otherButtonTitles:@"Settings", nil];

        alertView.tag = 300;

        [alertView show];

        return;
    }
}

// check if location service is enabled (ref: https://stackoverflow.com/a/35982887/2298002)
+ (void)checkLocationServicesEnabled
{
    //Checking authorization status
    if (![CLLocationManager locationServicesEnabled] || [CLLocationManager authorizationStatus] == kCLAuthorizationStatusDenied)
    {

        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Location Services Disabled!"
                                                            message:@"You need to enable your GPS location right now!!"
                                                           delegate:self
                                                  cancelButtonTitle:@"Cancel"
                                                  otherButtonTitles:@"Settings", nil];

        //TODO if user has not given permission to device
        if (![CLLocationManager locationServicesEnabled])
        {
            alertView.tag = 100;
        }
        //TODO if user has not given permission to particular app
        else
        {
            alertView.tag = 200;
        }

        [alertView show];

        return;
    }
}

// handle bringing user to settings for each
+ (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{

    if(buttonIndex == 0)// Cancel button pressed
    {
        //TODO for cancel
    }
    else if(buttonIndex == 1)// Settings button pressed.
    {
        if (alertView.tag == 100)
        {
            //This will open ios devices location settings
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=LOCATION_SERVICES"]];
        }
        else if (alertView.tag == 200)
        {
            //This will open particular app location settings
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
        }
        else if (alertView.tag == 300)
        {
            //This will open particular app location settings
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
        }
    }
}

GLHF !

在最新版本的iOS中，这种方法已被弃用。支持iOS 7和iOS 8使用:

UIApplication *application = [UIApplication sharedApplication];

BOOL enabled;

// Try to use the newer isRegisteredForRemoteNotifications otherwise use the enabledRemoteNotificationTypes.
if ([application respondsToSelector:@selector(isRegisteredForRemoteNotifications)])
{
    enabled = [application isRegisteredForRemoteNotifications];
}
else
{
    UIRemoteNotificationType types = [application enabledRemoteNotificationTypes];
    enabled = types & UIRemoteNotificationTypeAlert;
}

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。