如何使用Swift 3.0中的NotificationCenter和swift 2.0中的NSNotificationCenter传递数据？

我正在我的swift ios应用程序中实现socket.io 。

目前在几个面板上我正在监听服务器并等待收到的消息。 我是通过在每个面板中调用getChatMessage函数来实现的： 

 func getChatMessage(){ SocketIOManager.sharedInstance.getChatMessage { (messageInfo) -> Void in dispatch_async(dispatch_get_main_queue(), { () -> Void in //do sth depending on which panel user is }) } }

但是我注意到这是一个错误的方法，我需要更改它 – 现在我想开始只收听一次传入消息，当有任何消息出现时 – 将此消息传递给任何监听它的面板。

所以我想通过NSNotificationCenter传递传入的消息。 到目前为止，我能够传递发生事件的信息，但不能传递数据本身。 我是这样做的： 

 NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(ViewController.showSpinningWheel(_:)), name: showSpinner, object: nil)

然后我有一个叫做的函数： 

 func showSpinningWheel(notification: NSNotification) { }

任何时候我想打电话给我，我正在做： 

 NSNotificationCenter.defaultCenter().postNotificationName(hideSpinner, object: self)

那么如何传递对象messageInfo并将其包含在被调用的函数中呢？

Swift 2.0

使用userInfo传递信息，这是一个类型为[NSObject：AnyObject]的可选字典？ 

  let imageDataDict:[String: UIImage] = ["image": image] // Post a notification NSNotificationCenter.defaultCenter().postNotificationName(notificationName, object: nil, userInfo: imageDataDict) // Register to receive notification in your class NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: notificationName, object: nil) // handle notification func showSpinningWheel(notification: NSNotification) { if let image = notification.userInfo?["image"] as? UIImage { // do something with your image } }

Swift 3.0版

userInfo现在需要[AnyHashable：Any]？ 作为参数，我们在Swift中作为字典文字提供 

  let imageDataDict:[String: UIImage] = ["image": image] // post a notification NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) // `default` is now a property, not a method call // Register to receive notification in your class NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil) // handle notification func showSpinningWheel(_ notification: NSNotification) { if let image = notification.userInfo?["image"] as? UIImage { // do something with your image } }

注意：通知“名称”不再是字符串，而是Notification.Name类型，因此我们使用NSNotification.Name(rawValue:"notificationName") ，我们可以使用自己的自定义通知扩展Notification.Name。 

 extension Notification.Name { static let myNotification = Notification.Name("myNotification") } // and post notification like this NotificationCenter.default.post(name: .myNotification, object: nil)

您好@sahil我更新了您对swift 3的回答 

 let imageDataDict:[String: UIImage] = ["image": image] // post a notification NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) // `default` is now a property, not a method call // Register to receive notification in your class NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil) // handle notification func showSpinningWheel(_ notification: NSNotification) { print(notification.userInfo ?? "") if let dict = notification.userInfo as NSDictionary? { if let id = dict["image"] as? UIImage{ // do something with your image } } }

希望它有用。 谢谢

对于Swift 3 

 let imageDataDict:[String: UIImage] = ["image": image] // post a notification NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) // `default` is now a property, not a method call // Register to receive notification in your class NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil) // handle notification func showSpinningWheel(_ notification: NSNotification) { print(notification.userInfo ?? "") if let dict = notification.userInfo as NSDictionary? { if let id = dict["image"] as? UIImage{ // do something with your image } } }

对于Swift 4 

 let imageDataDict:[String: UIImage] = ["image": image] // post a notification NotificationCenter.default.post(name: NSNotification.Name(rawValue: "notificationName"), object: nil, userInfo: imageDataDict) // `default` is now a property, not a method call // Register to receive notification in your class NotificationCenter.default.addObserver(self, selector: #selector(self.showSpinningWheel(_:)), name: NSNotification.Name(rawValue: "notificationName"), object: nil) // handle notification @objc func showSpinningWheel(_ notification: NSNotification) { print(notification.userInfo ?? "") if let dict = notification.userInfo as NSDictionary? { if let id = dict["image"] as? UIImage{ // do something with your image } } }

let dictionary = self.convertStringToDictionary（responceString）
NotificationCenter.default.post（name：NSNotification.Name（rawValue：“SOCKET_UPDATE”），object：dictionary）

Interesting Posts