我实际上是通过JSON和消息接收通知的，所以我想要的是处理通知并将其显示给用户。
当应用程序没有运行或在后台时，消息会显示，但当应用程序打开时，没有通知。事实上，我在didReceiveRemoteNotification时收到了json，但我想要的是一个像whatsapp做的那样的通知框。
就像这样：

我有这个：

func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {
    print("Notification received: \(userInfo)")
    let notification = userInfo["aps"] as? NSDictionary
    let message = notification?.valueForKey("alert")
}

而这在didfinishlaunchWithOptions

let readAction = UIMutableUserNotificationAction()
        readAction.identifier = "READ_IDENTIFIER"
        readAction.title = "Read"
        readAction.activationMode = UIUserNotificationActivationMode.Foreground
        readAction.destructive = false
        readAction.authenticationRequired = true

        let deleteAction = UIMutableUserNotificationAction()
        deleteAction.identifier = "DELETE_IDENTIFIER"
        deleteAction.title = "Delete"
        deleteAction.activationMode = UIUserNotificationActivationMode.Foreground
        deleteAction.destructive = true
        deleteAction.authenticationRequired = true

        let ignoreAction = UIMutableUserNotificationAction()
        ignoreAction.identifier = "IGNORE_IDENTIFIER"
        ignoreAction.title = "Ignore"
        ignoreAction.activationMode = UIUserNotificationActivationMode.Foreground
        ignoreAction.destructive = false
        ignoreAction.authenticationRequired = false

        let messageCategory = UIMutableUserNotificationCategory()
        messageCategory.identifier = "MESSAGE_CATEGORY"
        messageCategory.setActions([readAction, deleteAction], forContext: UIUserNotificationActionContext.Minimal)
        messageCategory.setActions([readAction, deleteAction, ignoreAction], forContext: UIUserNotificationActionContext.Default)

        let types: UIUserNotificationType = [UIUserNotificationType.Badge, UIUserNotificationType.Sound, UIUserNotificationType.Alert]

        application.registerUserNotificationSettings(
            UIUserNotificationSettings(
                forTypes: types,
                categories: (NSSet(array: [messageCategory])) as? Set<UIUserNotificationCategory>))

        UIApplication.sharedApplication().registerForRemoteNotifications()

        let notTypes:UIUserNotificationType = [UIUserNotificationType.Alert, UIUserNotificationType.Badge, UIUserNotificationType.Sound]
        let noteSettings:UIUserNotificationSettings = UIUserNotificationSettings(forTypes: notTypes, categories: nil)

        UIApplication.sharedApplication().registerUserNotificationSettings(noteSettings)

希望有人能帮上忙。谢谢大家