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

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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通过在每个面板中调用 getChatMessage 函数来实现这一目的：

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？

ios swift swift3 nsnotificationcenter nsnotifications

4 回答

  • 213

    Swift 2.0

    使用 userInfo 传递信息，这是[NSObject：AnyObject]类型的可选字典？

    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 version

    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   
  }
 }

    NOTE: 通知“names”不再是字符串，但是Notification.Name类型，因此我们使用 NSNotification.Name(rawValue:"notificationName") 的原因，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)
    回复于
  • 1

    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

    回复于
  • 14

    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
            }
        }
 }
    回复于
  • 12

    let dictionary = self.convertStringToDictionary（responceString）
    NotificationCenter.default.post（名称：NSNotification.Name（rawValue："SOCKET_UPDATE"），对象：字典）

    回复于

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