修改另一个视图控制器的对象-Modifyinganobjectofanotherviewcontroller

2  

You can use the NotificationCenter to send and receive internal notifications (note they are different from local and remote notifications).

您可以使用NotificationCenter发送和接收内部通知(请注意它们与本地和远程通知不同)。

First create your notification doing something like this:

首先创建这样的通知:

extension Notification.Name {
    static let remoteNotificatiOnReceived= Notification.Name("uk.co.company.app.remoteNotificationReceived")
}

Then in your view controller that is to respond do something like this:

然后在你的视图控制器中响应做这样的事情:

class TestViewController: UIViewController {
    var remoteNotificationReceivedObserver: NSObjectProtocol?

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        remoteNotificatiOnReceivedObserver= NotificationCenter.default.addObserver(forName: Notification.Name.remoteNotificationReceived, object: nil, queue: nil, using: { (notification) in
            DispatchQueue.main.async { // because the notification won't be received on the main queue and you want to update the UI which must be done on the main queue.
                // Put the code to change the button here
            }
        })
    }

    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)

        if let remoteNotificatiOnReceivedObserver= remoteNotificationReceivedObserver {
            NotificationCenter.default.removeObserver(remoteNotificationReceivedObserver)
        }
    }
}

Then elsewhere in you app you post the notification like this:

然后在你的应用程序的其他地方发布通知,如下所示:

    NotificationCenter.default.post(name: Notification.Name.remoteNotificationReceived, object: nil)

2  

You can use NotificationCenter! add observer in your view controller and remove it while you go back from that view controller(custom notification). and when you receive notification post it!

您可以使用NotificationCenter!在视图控制器中添加观察者并在从该视图控制器返回时将其删除(自定义通知)。当你收到通知后发布它!

If you don't have idea that how to deal with NotificationCenter then refer This SO post !

如果您不知道如何处理NotificationCenter,请参阅此SO帖子!

1  

The only place you should really be interacting with another vew controller like that is during segues (if you are using Storyboards). Even then, you should let the view functions for that controller be responsible for changing the state of its buttons and just pass some variable to the controller or perhaps better set up the controller to listen for notifications. Then your app delegate, or other controller can just post notifications that your home controller listens for.

你应该真正与另一个vew控制器进行交互的唯一地方就是segues(如果你使用的是Storyboard)。即便如此,您应该让该控制器的视图函数负责更改其按钮的状态,并将一些变量传递给控制器​​,或者更好地设置控制器以监听通知。然后您的应用程序委托或其他控制器只能发布您的家庭控制器侦听的通知。

1  

It is possible, but addressing directly members of another ViewController breaks responsibility. It is a good practice to define Interface protocols for internal interactions. In this particular case, it is a good idea to create protcol RemoteNotificationReciverInterface (or kind of RemoteNotificationReciveable according to some modern coding styles advice, although I found it difficult to find appropriate adjective in this case) :

这是可能的,但直接解决另一个ViewController的成员会破坏责任。为内部交互定义接口协议是一种很好的做法。在这种特殊情况下,根据一些现代编码样式建议创建protcol RemoteNotificationReciverInterface(或者RemoteNotificationReciveable的类型是一个好主意,尽管我发现在这种情况下很难找到合适的形容词):

protocol RemoteNotificationReciverInterface: class {
    func didReciveNotification(info : [AnyHashable : Any])
}

Then extent your ViewController( and any view controllers that had to react on Notifications when they are topmost)

然后扩展您的ViewController(以及任何视图控制器,当它们位于最顶层时必须对通知作出反应)

extension HomeViewController: RemoteNotificationReciverInterface {
    func didReciveNotification(info : [AnyHashable : Any]) {
        // Chnage you button, ignore para,eters
    }
}

You can adopt UINavigationContoroller, UITabBarConroller etc. to forward notifications to their topmost controllers, like:

您可以采用UINavigationContoroller,UITabBarConroller等将通知转发给最顶层的控制器,例如:

extension UINavigationController: RemoteNotificationReciverInterface {
    func didReciveNotification(info : [AnyHashable : Any]) {
        (topViewController as? RemoteNotificationReciverInterface)?.didReciveNotification(info: info)
    }
}

And the easily forward it from app delegate.

并且可以从app delegate轻松转发它。

func application(_ application: UIApplication,didReceiveRemoteNotification userInfo: [AnyHashable : Any],fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
    if application.applicatiOnState== .active {
        (window?.rootViewController as? RemoteNotificationReciverInterface).didReciveNotification(info: userInfo)
    }
}