尽管Zac的答案在iOS 7之前是完全正确的，但自从iOS 8到来后，它就发生了变化。因为enabledRemoteNotificationTypes从iOS 8开始就已经弃用了。对于iOS 8和更高版本，你需要使用isregisteredforremotenotifizations。

—>使用enabledRemoteNotificationTypes >使用isregisteredforremotenotifizations。

尽管Zac的答案在iOS 7之前是完全正确的，但自从iOS 8到来后，它就发生了变化。因为enabledRemoteNotificationTypes从iOS 8开始就已经弃用了。对于iOS 8和更高版本，你需要使用isregisteredforremotenotifizations。

—>使用enabledRemoteNotificationTypes >使用isregisteredforremotenotifizations。

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
    }

quantumpotato的问题:

类型是由

UIRemoteNotificationType types = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];

可以使用

if (types & UIRemoteNotificationTypeAlert)

而不是

if (types == UIRemoteNotificationTypeNone) 

将允许你只检查通知是否启用(不用担心声音，徽章，通知中心等)。第一行代码(types & UIRemoteNotificationTypeAlert)如果“Alert Style”设置为“横幅”或“警报”将返回YES，如果“Alert Style”设置为“None”则返回NO，与其他设置无关。

下面是一个完整的例子，涵盖了iOS8和iOS7(以及更低版本)。请注意，在iOS8之前，你无法区分“禁用远程通知”和“仅启用锁屏查看”。

BOOL remoteNotificationsEnabled = false, noneEnabled,alertsEnabled, badgesEnabled, soundsEnabled;

if ([[UIApplication sharedApplication] respondsToSelector:@selector(registerUserNotificationSettings:)]) {
    // iOS8+
    remoteNotificationsEnabled = [UIApplication sharedApplication].isRegisteredForRemoteNotifications;

    UIUserNotificationSettings *userNotificationSettings = [UIApplication sharedApplication].currentUserNotificationSettings;

    noneEnabled = userNotificationSettings.types == UIUserNotificationTypeNone;
    alertsEnabled = userNotificationSettings.types & UIUserNotificationTypeAlert;
    badgesEnabled = userNotificationSettings.types & UIUserNotificationTypeBadge;
    soundsEnabled = userNotificationSettings.types & UIUserNotificationTypeSound;

} else {
    // iOS7 and below
    UIRemoteNotificationType enabledRemoteNotificationTypes = [UIApplication sharedApplication].enabledRemoteNotificationTypes;

    noneEnabled = enabledRemoteNotificationTypes == UIRemoteNotificationTypeNone;
    alertsEnabled = enabledRemoteNotificationTypes & UIRemoteNotificationTypeAlert;
    badgesEnabled = enabledRemoteNotificationTypes & UIRemoteNotificationTypeBadge;
    soundsEnabled = enabledRemoteNotificationTypes & UIRemoteNotificationTypeSound;
}

if ([[UIApplication sharedApplication] respondsToSelector:@selector(registerUserNotificationSettings:)]) {
    NSLog(@"Remote notifications enabled: %@", remoteNotificationsEnabled ? @"YES" : @"NO");
}

NSLog(@"Notification type status:");
NSLog(@"  None: %@", noneEnabled ? @"enabled" : @"disabled");
NSLog(@"  Alerts: %@", alertsEnabled ? @"enabled" : @"disabled");
NSLog(@"  Badges: %@", badgesEnabled ? @"enabled" : @"disabled");
NSLog(@"  Sounds: %@", soundsEnabled ? @"enabled" : @"disabled");

re:

这是正确的

if (types & UIRemoteNotificationTypeAlert)

但是下面也是正确的!(因为UIRemoteNotificationTypeNone是0)

if (types == UIRemoteNotificationTypeNone) 

参见以下内容

NSLog(@"log:%d",0 & 0); ///false
NSLog(@"log:%d",1 & 1); ///true
NSLog(@"log:%d",1<<1 & 1<<1); ///true
NSLog(@"log:%d",1<<2 & 1<<2); ///true
NSLog(@"log:%d",(0 & 0) && YES); ///false
NSLog(@"log:%d",(1 & 1) && YES); ///true
NSLog(@"log:%d",(1<<1 & 1<<1) && YES); ///true
NSLog(@"log:%d",(1<<2 & 1<<2) && YES); ///true