First of all, wechat users need to log in automatically to check the session. If the session expires, log in again

 wx.checkSession({
        success: function (res) {
        },
        fail: function (res) {
          console.log("Need to sign in again");
          wx.login({
            success(res) {
              if (res.code) {
                console.log("User login voucher" + res.code);
                wx.request({
                  url: 'http://localhost:62923/index.aspx',
                  data: {
                    code: res.code,
                  },
                  success(res) {
                    console.log("Obtain openid: " + res.data.openid + "  session_key: " + res.data.session_key);
                  }
                })
              }
            }


          });

        }
      });

Login obtains code to exchange openid (user unique ID) and session key (decode encrypted information) from the background

 string js_code = Request.QueryString["code"];
        string serviceAddress = "https://api.weixin.qq.com/sns/jscode2session?appid=wxd4137ad6add09a40&secret=c147d93a4a810d42e0b4bde3a0d3fb51&js_code=" + js_code + "&grant_type=authorization_code";
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(serviceAddress);
        request.Method = "GET";
        request.ContentType = "text/html;charset=UTF-8";
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        Stream myResponseStream = response.GetResponseStream();
        StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.UTF8);
        string retString = myStreamReader.ReadToEnd();
        myStreamReader.Close();
        myResponseStream.Close();
        Response.Write(retString);

Load user information (Revision) now use data component or button

//wx.getUserInfo({

// data: { withCredentials: true },

// success(res) {

// console.log(res.userInfo.nickName + "/");

// }

// });

Then, configure the Socket service - hpsocket = > httpserver to create websocket

(1) HP socket requires that hpsocket4c u.dll and HPSocketCS.DLL must be 32-bit and 64 bit is useless

(2) the applet connection cannot be placed in app.js, otherwise it cannot be connected and the handshake is stuck all the time.

const app = getApp();
const config = app.config;
const wafer = require('../../vendors/wafer-client-sdk/index');
const lab = require('../../lib/lab');

Page({
  data: {
    status: 'waiting',
    url: 'wss://' + config.host + '/ws',
    connecting: false,
    hintLine1: 'Complete server development,',
    hintLine2: 'Let the server support WebSocket Connect'
  },

  /**
   * WebSocket Connected or not
   */
  socketOpen: false,

  /**
   * Start connecting to WebSocket
   */
  connect() {
    this.setData({
      status: 'waiting',
      connecting: true,
      hintLine1: 'on connection',
      hintLine2: '...'
    });
    this.listen();
    wafer.setLoginUrl(`https://${config.host}/login`);
    wafer.login({
      success: () => {
        const header = wafer.buildSessionHeader();
        const query = Object.keys(header).map(key => `${key}=${encodeURIComponent(header[key])}`).join('&');
        wx.connectSocket({
          // The wx.connectSocket() API header parameter of the applet is invalid. Attach the session information to the URL
          url: `${this.data.url}?${query}`,
          header
        });
      },
      fail: (err) => {
        this.setData({
          status: 'warn',
          connecting: false,
          hintLine1: 'Login failed',
          hintLine2: err.message || err
        });
      }
    });
  },

  /**
   * Listen to WebSocket events
   */
  listen() {
    wx.onSocketOpen(() => {
      this.socketOpen = true;
      this.setData({
        status: 'success',
        connecting: false,
        hintLine1: 'Successful connection',
        hintLine2: 'Now you can go through WebSocket Sent and received message'
      });
      console.info('WebSocket Connected');
    });
    wx.onSocketMessage((message) => {
      this.setData({
        hintLine2: message.data
      });
      lab.finish('websocket');
    });
    wx.onSocketClose(() => {
      this.setData({
        status: 'waiting',
        hintLine1: 'WebSocket Closed'
      });
      console.info('WebSocket Closed');
    });
    wx.onSocketError(() => {
      setTimeout(() => {
        this.setData({
          status: 'warn',
          connecting: false,
          hintLine1: 'Error occurred',
          hintLine2: 'WebSocket Connection establishment failed'
        });
      });
      console.error('WebSocket error');
    });
  },

  /**
   * Send a message with current time information
   */
  send() {
    wx.sendSocketMessage({
      data: new Date().toTimeString().split(' ').shift() + '.' + (new Date().getMilliseconds())
    });
  },
  
  /**
   * Close WebSocket connection
   */
  close() {
    this.socketOpen = false;
    wx.closeSocket();
  }
});

The next step is reverse proxy, because it must be accessed by wss legal domain name and forwarded to ws.