微信小程序文件上传坑返回数据需转为json

1、调用微信文件上传方法时，需要将返回的数据转为json,以下为封装的公用请求

  upload() {
    if (this.isLoad) {
      wx.showLoading({
        title: "加载中",
        mask: true
      });
    }
    let self = this;
    // //构建params，在params上面加上用户id,时间戳和签名
    // try {
    //   let customerId = wx.getStorageSync('customerId');
    //   if (null != customerId && customerId != undefined && customerId.length > 0) {
    //     self.params.customerId = customerId;
    //   }
    // } catch (e) {}

    // self.params.timestamp = new Date().getTime();
    // self.params.sign = self.generateSign();

    console.log("文件上传请求接口：" + self.method)
    console.log("请求报文：")
    console.log(self.formData)
    if (self.port.length > 0) {
      self.url += ':' + self.port + '/';
    }
    // 文件上传
    wx.uploadFile({
      url: self.url + self.method,
      filePath: self.filePath,
      name: 'file',
      header:{
        'cookie': wx.getStorageSync("sessionid")
      },
      formData: self.formData,
      success: function(res) {
        let JsonSrc =  JSON.parse(res.data)
        console.log("json转换：",JsonSrc)

        let response = JsonSrc;
        if (null != response &&
            response != undefined) {
          let rspCode = response.code;

          if ('0' == rspCode) {
            self.success(response);
          } else {
            if (self.fail(response)) {
              let rspMsg = response.msg;
              if (null != rspMsg &&
                  rspMsg != undefined &&
                  rspMsg.length > 0) {
                wx.showModal({
                  title: '提示',
                  showCancel: false,
                  content: rspMsg
                });
              }
            }
          }
        }
      },
      fail: function(response) {
        self.fail(response);
        wx.showModal({
          title: '提示',
          showCancel: false,
          content: "连接失败"
        });
      },
      complete: function(response) {
        wx.hideLoading();
        self.complete(response);
        console.log("应答报文：")
        console.log(response.data)
        let statusCode = response.statusCode;
        if (404 == statusCode) {
          self.fail(response);
          wx.showModal({
            title: '提示',
            showCancel: false,
            content: "服务器找不到请求的内容"
          });
        } else if (200 == statusCode) {
          console.log("文件请求", response)
         let JsonSrc =  JSON.parse(response.data)
          console.log("json转换：",JsonSrc)
          let rspCode = JsonSrc.code;
          if (null == rspCode ||
              rspCode == undefined ||
              rspCode == 40001) {
            wx.reLaunch({
              url: '../login/login'
            })
          }
        }

      }
    })