https://developers.weixin.qq.com/miniprogram/dev/extended/weui/uploader.html

//上传图片文件
  uplaodFile(files) {
    // 文件上传的函数，返回一个promise
    return new Promise((resolve, reject) => {

      var tempFilePaths = files.tempFilePaths;
      //上传返回值
      for (var i = 0; i < tempFilePaths.length; i++) {
        wx.uploadFile({
          url: app.globalData.urlCarPic,
          filePath: tempFilePaths[i],
          name: 'file',
          success: function (res) {
            var data = JSON.parse(res.data)
            var urls = data.url
            resolve({
                urls
              }),
            reject(res)
          },
          fail: function (err) {
            console.log(err)
          }
        })
      }


    })
  },

  uploadSuccess(e) {
      var url = e.detail.urls
      this.setData({
        drivefiles: this.data.drivefiles.concat(url),
    })
  },