如果我使用 TabBar Navigation，如何从 AppDelegate 调用 viewcontroller 方法

Question

当我的应用程序打开时，我真的需要帮助来调用视图控制器方法，尤其是在使用 TabBar 导航时。当我在通知到达时打开我的应用程序时，它会调用 didReceiveRemoteNotification 因为我启用了“content-available = 1”。但是，问题是我不知道如何访问我的 HomeViewController 方法 refresh() 因为我使用 TabBar 导航。我需要调用 HomeViewController refresh() didReceiveRemoteNotification 内部的方法，因为它确实需要从核心刷新数据，并且到达的通知保存在核心数据中。

每次收到通知时，我都会将它们保存在领域数据库中并在HomeViewController显示用户

func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject], fetchCompletionHandler handler: (UIBackgroundFetchResult) -> Void) {
    if let aps = userInfo["aps"] as? NSDictionary{
        if let alert = aps["alert"] as? NSDictionary{
            if let mbody = alert["body"] as? String{
                print("Message Body : \(body)")
                body = mbody
            }
            if let mtitle = alert["title"] as? String{
                print("Message Title : \(title)")
                title = mtitle
            }
        }
    }

    let newNotification = NotificationList()
    newNotification.title = title
    newNotification.body = body
    //Realm insert query
    oneSignalHelper.insertOneSignalNotification(newNotification)

    print("Remote Receive")
    //This condition isn't working
    if let viewController = self.window?.rootViewController as? HomeViewController {
        print("Remote Receive Read")
        //This method is HomeViewController method which I gonna use for refresh when I tapped notification.It read that are save in realm database and show results.
        viewController.readNotificationsAndUpdateUI()
    }

    handler(UIBackgroundFetchResult.NewData)

}

这是来自HomeViewController的readNotificationsAndUpdateUI()

func readNotificationsAndUpdateUI(){
    notifications = realm.objects(NotificationList)
    self.notificationTableView.setEditing(false, animated: true)
    self.notificationTableView.reloadData()
    self.refreshControl?.endRefreshing()
}

Answer 1

我建议你使用 NSNotificationCenter，只需在 didReceiveRemoteNotification 中发布通知，如下所示：

NSNotificationCenter.defaultCenter().postNotificationName("refreshNotification", object: nil)

在viewDidLoad() 的 HomeViewController 中，您应该像这样订阅通知中心：

NSNotificationCenter.defaultCenter().addObserver( self, selector: "refresh", name: "refreshNotification", object: nil)

Answer 2

不确定是否有帮助，但我根据之前的答案以这种方式解决了

加载故事板

let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle:nil)

加载 ViewController（检查您的故事板中是否有此 ViewController 的标识符！） 让 bestellvorschlag = storyBoard.instantiateViewController(identifier: "Bestellvorschlag") 作为！ Bestellvorschlag

在 ViewController 上加载函数

bestellvorschlag.loaddata() //Loads CoreData into Array of artikels

也许用结果的数量来修改标签栏徽章

let tabbarcontroller = self.window?.rootViewController as! UITabBarController
    if bestellvorschlag.artikels.count > 0
    {
        if let tabItems = tabbarcontroller.tabBar.items {
            // Third Tab!
            let tabItem = tabItems[2]
            tabItem.badgeValue = bestellvorschlag.artikels.count.description
        }
    }

appDelegate 中的完整函数

func applicationDidBecomeActive(_ application: UIApplication) {
 let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
        let bestellvorschlag = storyBoard.instantiateViewController(identifier: "Bestellvorschlag") as! Bestellvorschlag
        bestellvorschlag.loaddata()

        let tabbarcontroller = self.window?.rootViewController as! UITabBarController
        if bestellvorschlag.artikels.count > 0
        {
            if let tabItems = tabbarcontroller.tabBar.items {
                // Third Tab!
                let tabItem = tabItems[2]
                tabItem.badgeValue = bestellvorschlag.artikels.count.description
            }
        }
    }