微信小程序，解决 Cannot read property 's

问题截图如下

问题代码如下

loginAct: () => {
  console.log("执行了");
  var that = this;
  wx.getStorage({
    key: 'user',
    success: function (res) {
      console.log("信息数据res为", res);
      that.setData({
        userInfo: res.data,
      }, () => {
        console.log("重新刷新数据");
      })
    }
  })
}

解决办法：loginAct: () => {}改成loginAct(){}

loginAct(){
  console.log("执行了");
  var that = this;
  wx.getStorage({
    key: 'user',
    success: function (res) {
      console.log("信息数据res为", res);
      that.setData({
        userInfo: res.data,
      }, () => {
        console.log("重新刷新数据");
      })
    }
  })
}