检查用户是否允许本地通知。 iOS 8. Obj-C

Question

如果用户允许本地通知，是否没有简单的测试方法？在我拒绝发送本地通知后，我在控制台中发现了一条警告。当相关事件发生时，它表示应用程序试图发送通知，即使用户不允许。我想在尝试显示通知之前检查它是否被允许。看到我的情况的评论，我该怎么做？

我的代码是：

app = [UIApplication sharedApplication]; 
-(void)showBackgroundNotification:(NSString *) message { 
//check if app is in background and check if local notifications are allowed. 
    if (app.applicationState == UIApplicationStateBackground /*&& LocalNotificationsAreAllowed*/){ 
     UILocalNotification *note = [[UILocalNotification alloc]init]; 
     note.alertBody = message; 
     note.fireDate = [NSDate dateWithTimeIntervalSinceNow:0.0]; 
     [app scheduleLocalNotification :note]; 
    } 
} 

我得到提示用户是否允许像这样：

UIUserNotificationSettings *settings; 
if ([app  respondsToSelector:@selector(registerUserNotificationSettings:)]) 
{ 
    settings = [UIUserNotificationSettings settingsForTypes:(UIUserNotificationTypeBadge|UIUserNotificationTypeAlert|UIUserNotification TypeSound) categories:nil]; 
    [app registerUserNotificationSettings:settings]; 
} 

我不能使用设置对象？

编辑：我想我已经解决了它。这似乎工作。

-(void)showBackgroundNotification:(NSString *) message { 
    if (app.applicationState == UIApplicationStateBackground && [app currentUserNotificationSettings].types != UIUserNotificationTypeNone){ 
     UILocalNotification *note = [[UILocalNotification alloc]init]; 
     note.alertBody = message; 
     note.fireDate = [NSDate dateWithTimeIntervalSinceNow:0.0]; 
     [app scheduleLocalNotification :note]; 
    } 
} 

Answer 1

下面是我用更少的具体情况：

+ (BOOL)notificationsEnabled { 
    UIUserNotificationSettings *settings = [[UIApplication sharedApplication] currentUserNotificationSettings]; 
    return settings.types != UIUserNotificationTypeNone; 
} 

我通常把一组这几种方法的通知经理。