/*用微信小程序token拿二维码*/
async fetchMINIQRcode({commit,state},params){
    var instance = axios.create({
      responseType: ‘blob‘, //返回数据的格式，可选值为arraybuffer,blob,document,json,text,stream，默认值为json
    })
let data = await instance.post(‘https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=‘ + params.access_token, params.params).then(res => res.data)
    return data;
  }


                          //拿值 MINI
                          if (MINI) {
                            var blob = new Blob([MINI], {
                              type: ‘application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8‘
                            });
                            t.QRcode = URL.createObjectURL(blob);
                            t.QRcode_col = true;
                          }