downLoadImg: function (netUrl, storageKeyUrl) {
    wx.getImageInfo({
      src: netUrl, //请求的网络图片路径
      success: function (res) {
        //请求成功后将会生成一个本地路径即res.path,然后将该路径缓存到storageKeyUrl关键字中
        wx.setStorage({
          key: storageKeyUrl,
          data: res.path,
        });

      }
    })
  },