使用NotificatinCenter处理用户键入通知时出现问题 [英] Issue while handle user typing notification using notificatincenter

问题描述

我正在使用socket.io创建一个聊天应用程序，每件事都很完美，但是当我处理用户键入通知时，却出现如下错误

I am creating an chat application using socket.io, every things going perfect but when I am handling user typing notification I am getting error like below

错误:

由于未捕获的异常而终止应用程序 'NSInvalidArgumentException'，原因:'-[SocketChat.ChatViewController handleUserTypingNotification:]:无法识别的选择器已发送到实例 0x7f817653d710

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[SocketChat.ChatViewController handleUserTypingNotification:]: unrecognized selector sent to instance 0x7f817653d710

现在，我将向您展示我的代码以实现更好的体验

and now I will show you my code for better expiation

代码:

private func listenForOtherMessages() {
    socket.on("userTypingUpdate") { (dataArray, socketAck) -> Void in
    NotificationCenter.default.post(name: NSNotification.Name(rawValue: "userTypingNotification"), object: dataArray[0] as? [String: AnyObject])}
}

在这里，我正在管理从index.js文件和另一个ViewController获取的方法.我通过波纹管这样的通知中心进行管理

Here I am managing method which I am getting from index.js file and from another viewcontroller. I manage with notification center like bellow

let notificationCenter4 = NotificationCenter.default
        notificationCenter4.addObserver(self, selector: Selector(("handleUserTypingNotification")), name:NSNotification.Name(rawValue: "userTypingNotification"), object: nil)

我不明白为什么会出现此错误，它的确切含义是什么.谁能帮我吗?

I don't understand why this error is coming and what does it exactly mean. Can any one please help me?

import UIKit

class ChatViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let notificationCenter4 = NotificationCenter.default
        notificationCenter4.addObserver(self, selector: #selector(handleUserTypingNotification)), name:NSNotification.Name(rawValue: "userTypingNotification"), object: nil)
    }

    func handleKeyboardDidShowNotification(notification: NSNotification) {
        if let userInfo = notification.userInfo {
            if let keyboardFrame = (userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
                conBottomEditor.constant = keyboardFrame.size.height
                view.layoutIfNeeded()
            }
        }
    }

}

推荐答案

您的选择器签名错误.看起来应该像这样.

Your selector signature is wrong. It should look like this.

let notificationCenter4 = NotificationCenter.default
notificationCenter4.addObserver(self, selector: #selector(handleKeyboardDidShowNotification(notification:)), name:NSNotification.Name(rawValue: "userTypingNotification"), object: nil)

在您的代码中，您正在创建一个 new 实例，而您可能已经有了一个选择器.像这样的东西.

In your code you are creating a new instance, while you probably have a selector already. Something like this.

@objc func handleKeyboardDidShowNotification(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        if let keyboardFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            conBottomEditor.constant = keyboardFrame.size.height
            view.layoutIfNeeded()
        }
    }
}

这篇关于使用NotificatinCenter处理用户键入通知时出现问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！