problem description:

Code javascript script code is as follows

onLoad() {
    let self = this
    // 
    if (cc.sys.isNative) {
        window.io = SocketIO
    } else {
        // socket.io.js
        require("socket.io")
    }
    let socket = io("ws://localhost:3000")
    socket.on("connected", (msg) => {
        console.log("..")
    })
    socket.emit("data", "dagger")
}