Question

我正在app.js中为createStackNavigator导入chatscreen.js。我在chatscreen.js中有var socket = socketio.getSocket();代码，当导入代码在app.js中运行时，此getSocket（）;运行。

我想运行socketio.socketConnect（）;在app.js中导入chatscreen.js之前，但我无法创建此逻辑

App.js

import ChatScreen from './components/ChatScreen/ChatScreen';
import socketio from './components/Classes/socketio';
import SplashScreen from './components/SplashScreen/SplashScreen';

class App extends Component{
    constructor(props){
        super(props); 
}
}
const RootStack = createStackNavigator(
    {
     Splash:{screen: SplashScreen},
     Chat:{screen: ChatScreen},
}

ChatScreen.js

import socketio from '../Classes/socketio';
var socket = socketio.getSocket();

class ChatScreen extends Component{

    constructor(props){
        super(props);  
}
}

socketio.js

import React, { Component } from 'react';
import io from "socket.io-client";

let socket;

class socketio extends Component{


    static socketConnect(domain){
                socket = io("http://"+domainToken,{jsonp:false})
    }

    static getSocket(){
        if (!socket) {
            throw new Error("Must call socketConnect() before getSocket()");
        }
        return socket;
    }
}

export default socketio;

Answer 1

问题出在您的socketio.js上，您使它成为一个类组件，而应该使它成为这样的功能组件：

import io from "socket.io-client";

let socket;


    function socketConnect(domain){
                socket = io("http://"+domainToken,{jsonp:false})
    }

    function getSocket(){
        if (!socket) {
            throw new Error("Must call socketConnect() before getSocket()");
        }
        return socket;
    }

module.exports = {
socketConnect,
getSocket
}

然后您可以像这样导入它：

import socketio from '../Classes/socketio';
var socket = socketio.getSocket();
class ChatScreen extends Component{

    constructor(props){
        super(props);  
}

componentDidMount(){
  socketio.socketConnect(domain)
}
}

React-Native Import类问题

1 个答案: