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

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;
    }
}];

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;
}

为了完成这个答案，它可以这样工作……

UIRemoteNotificationType types = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
switch (types) {
   case UIRemoteNotificationTypeAlert:
   case UIRemoteNotificationTypeBadge:
       // For enabled code
       break;
   case UIRemoteNotificationTypeSound:
   case UIRemoteNotificationTypeNone:
   default:
       // For disabled code
       break;
}

编辑:这是不对的。因为这些是位智慧的东西，它不会与开关工作，所以我结束使用这个:

UIRemoteNotificationType types = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
UIRemoteNotificationType typesset = (UIRemoteNotificationTypeAlert | UIRemoteNotificationTypeBadge);
if((types & typesset) == typesset)
{
    CeldaSwitch.chkSwitch.on = true;
}
else
{
    CeldaSwitch.chkSwitch.on = false;
}

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

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;
}