Swift: 当两个视图彼此没有直接联系时，是否可以使用委托？

Question

我有三个 ViewController：ViewController1、ViewController2 和 ViewController3。

ViewController1 在屏幕上推送 ViewController2，两个视图可以通过委托相互交互。

ViewController2 将 ViewController3 推到屏幕上。

现在可以在ViewController1和ViewController3之间建立一个委托吗？我希望 ViewController3 能够操作 ViewController1 的标签。

Answer 1

这种情况下的最佳方式是 Notification 模式

  // Notification posting
  NotificationCenter.default.post(name: NSNotification.Name(rawValue: "fromViewController3"), object: nil, userInfo: myDict) 


 // Register in ViewController1 to receive notification in your class ViewController1
 NotificationCenter.default.addObserver(self, selector: #selector(self.manipulateMyLabel(_:)), name: NSNotification.Name(rawValue: "fromViewController3"), object: nil)

 // handle notification
 func manipulateMyLabel(_ notification: NSNotification) {
        print(notification.userInfo ?? "")
        if let dict = notification.userInfo as NSDictionary? {
            if let newString = dict["labelValue"] as? String {
               // user newString to update the label text or something.
            }
        }
 }

Swift: 当两个视图彼此没有直接联系时，是否可以使用委托？

Swift: Is it possible to use delegation when both views aren't in direct connection with each other?

ios

swift

swift-protocols