ios - 收到推送通知时使用协议(protocol)更新 UIViewController？

Question

这是在 AppDelegate 中收到推送通知后通知 UIViewController 的正确方法吗？ UIViewController 需要在收到推送通知后刷新其内容。 Swift 新手，因此想确认这是 Swift 中的有效方法。

应用程序委托(delegate):

protocol PushNotificationDelegate : class {
    func didReceivePushNotification()
}


@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    var pushDelegates = [PushNotificationDelegate]()

    ...

    func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {
        PFPush.handlePush(userInfo)
        if application.applicationState == UIApplicationState.Inactive {
            PFAnalytics.trackAppOpenedWithRemoteNotificationPayload(userInfo)
        }

        // Notify delegates
        for delegate in pushDelegates {
            delegate.didReceivePushNotification()
        }
    }


    func addPushNotificationDelegate(newDelegate: PushNotificationDelegate) {
        if (pushDelegates.indexOf{$0 === newDelegate} == nil) {
            pushDelegates.append(newDelegate)
        }
    }
}

UIViewController:

class HomeViewController: UIViewController, PushNotificationDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

        ...

        // Get notified when push notifications come in
        if let delegate = UIApplication.sharedApplication().delegate as? AppDelegate {
            delegate.addPushNotificationDelegate(self)
        }
    }


   func didReceivePushNotification() {

   }
   }

Answer 1

嗯，这一切看起来都很好，而且很符合 Swift 的习惯。需要记住的一件事是，当 View Controller 被解除时，您需要确保从 AppDelegate 中维护的委托(delegate)列表中删除 View Controller 。否则，您的 View Controller 将不会从内存中删除。您可以在 HomeViewController 中实现该代码:

-(void)viewWillDisappear(animated:Bool){
   [super viewWillDisappear]
//Remove 'self' from the delegate array maintained in AppDelegate.
}