推送权限

#if __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0
    [[UNUserNotificationCenter currentNotificationCenter] getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {
        if (settings.authorizationStatus == UNAuthorizationStatusAuthorized) {
            if (returnBlock) {
                returnBlock(BestWebMessageCallbackResultStatusSuccess);
            }
        }
        else {
            if (@available(iOS 12.0, *)) {
                if(settings.authorizationStatus == UNAuthorizationStatusProvisional)
                {
                    NSLog(@"临时的");
                    if (returnBlock) {
                        returnBlock(BestWebMessageCallbackResultStatusSuccess);
                    }
                }
            }
            else {
                if (returnBlock) {
                    returnBlock(BestWebMessageCallbackResultStatusFailure);
                }
            }
        }
    }];

#elif __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_8_0
    UIUserNotificationSettings *settings = [[UIApplication sharedApplication] currentUserNotificationSettings];
    if (settings.types == UIUserNotificationTypeNone) {
         NSLog(@"禁止");
        if (returnBlock) {
            returnBlock(BestWebMessageCallbackResultStatusFailure);
        }
    }
    else {
        NSLog(@"允许");
        if (returnBlock) {
            returnBlock(BestWebMessageCallbackResultStatusSuccess);
        }
    }
#else
    UIRemoteNotificationType type = [[UIApplication sharedApplication] enabledRemoteNotificationTypes];
    if (type == UIRemoteNotificationTypeNone) {
        NSLog(@"禁止");
        if (returnBlock) {
            returnBlock(BestWebMessageCallbackResultStatusFailure);
        }
    }
    else {
        NSLog(@"允许");
        if (returnBlock) {
            returnBlock(BestWebMessageCallbackResultStatusSuccess);
        }
    }
#endif