[网络协议]微信小程序websocket正确姿势

1.请求地址必须是ws://或wss://

var?wsurl?=?'wss://zsj.itdos.net/v1'

2.服务端websocket必须返回文件头protocol

小程序端请求会发送protocol，服务端必须取得这个再发回去？

go语言这样处理：https://studygolang.com/articles/22255?fr=sidebar

websocket包采用的是github.com/gorilla/websocket

    var upgrade = websocket.Upgrader{
        // cross origin domain
        CheckOrigin: func(r *http.Request) bool {   //这个是解决跨域问题
            return true
        },
        Subprotocols:[]string{s.Ctx.Input.Header("Sec-WebSocket-Protocol")},  
        //将获取的参数放进这个数组，问题解决
    }

3.小程序wss请求带上sessionid，才能进行用户判断

?https://blog.csdn.net/zhangheng028/article/details/50352564

4.上小程序代码

// 计算
  formSubmit: function (e) {
    var that = this;
    if (that.data.NumberError != null) {
      wx.showToast({
        title: "输入存在错误",
        icon: 'none',
        duration: 2000
      });
      return;
    }
    //清除计时器  即清除setInter
    clearInterval(that.data.setInter)
    that.setData({
      canDownload: false,
      num: 0,
      canCalculate: false
    })
    //将计时器赋值给setInter
    that.data.setInter = setInterval(
      function () {
        var numVal = that.data.num + 1;
        that.setData({
          num: numVal
        });
      }, 1000);
    var sessionId = wx.getStorageSync('sessionId')
    var apiUrl = config.wsurl + '/mathcad/postwxmath2/' + that.data.id+'?hotqinsessionid='+sessionId;

    var obj = {};
    obj.message = new Date().toLocaleString();
    obj.templeid = that.data.id
    obj.inputdata = e.detail.value
    obj = JSON.stringify(obj); //将JSON对象转化为JSON字符

    let SocketTask = wx.connectSocket({
      url: apiUrl, //'wss://example.qq.com',
      header: {
        'content-type': 'application/json'
      },
      protocols: ['protocol1'],
      method: "GET",
      success: function (res) {
        console.log(res)
      }
    })

    SocketTask.onOpen(function (res) {
      // console.log('WebSocket连接已打开！')
      SocketTask.send({
        data: obj, //postData,
        success: function () {
          console.log('发送成功')
          // console.log(obj)
        },
        fail: function (err) {
          console.log('发送失败')
          console.log(err)
          // 停止计时器
          clearInterval(that.data.setInter)
        }
      })
    })

    SocketTask.onClose(function (res) {
      console.log('WebSocket连接已关闭！')
    })

    SocketTask.onMessage(function (res) {
      // console.log('接收到的消息：' + res.data)
      var msg = JSON.parse(res.data);
      var tmpArr = that.data.wsMessage + msg.message + '\n';
      that.setData({
        wsMessage: tmpArr
      })
      if (msg.info == "ERROR") {
        //清除计时器  即清除setInter
        clearInterval(that.data.setInter)
        that.setData({
          canCalculate: true
        })
        wx.showToast({
          title: msg.data.info,
          icon: 'none',
          duration: 2000
        })
      } else if (msg.info == "SUCCESS") {
        // 停止计时器
        clearInterval(that.data.setInter)
        that.setData({
          mathcaloutput: msg.data,
          canDownload: true,
          canCalculate: true,
          pdflink: msg.pdflink
        })
      }
    })
  },