小程序upload异步问题

Question

小程序想通过上传图片后将图片位置存储在云函数的字段里，但返回的结果是个[]空的值，无法保存在云函数字段里，可能是异步问题

运行结果及报错内容

    async chooseImg(e) {
        await this.chooseImg2(e)

        await wx.cloud.callFunction({
            name: "deliver_table",
            data: {
                id: this.data.dataList[e.currentTarget.dataset.index]._id,
                deliver_place: this.data.dataList[e.currentTarget.dataset.index].deliver_place
            },
        })
    },
    async chooseImg2(e) {
        let that = this
        var val = e.detail.value;
        let index = e.currentTarget.dataset.index
        console.log(index)
        wx.chooseImage({
            count: 2,
            sizeType: ['compressed'],
            sourceType: ['album', 'camera'],
            success(res) {
                // tempFilePath可以作为 img 标签的 src 属性显示图片
                const tempFilePaths = res.tempFilePaths
                console.log(tempFilePaths)
                for (let i = 0; i < tempFilePaths.length; i++) {
                    wx.cloud.uploadFile({
                        cloudPath: "deliver_place/" + Date.now() + ".jpg",
                        filePath: tempFilePaths[i]
                    }).then(res => {
                        console.log(res)
                        let deliver_place = 'dataList[' + index + '].deliver_place[' + i + ']'
                        that.setData({
                            [deliver_place]: res.fileID
                        })
                        console.log(that.data.dataList)
                    })
                }
            }
        })
    },

Answer 1

写个demo

<button bindtap="chooseImage">选择图片</button>

// pages/demo/demo.js
Page({
  data: {
    fileArr: []
  },

  // 选择图片
  chooseImage() {
    wx.chooseImage({
      count: 2,
      success: async res => {
        const { tempFilePaths } = res
        let { fileArr } = this.data
        for (const item of tempFilePaths) {
          // 同步等待
          const result = await this.uploadImage(item)
          fileArr.push(result)
        }
        console.log(fileArr);
      }
    })
  },
  // 上传图片
  uploadImage(filePath) {
    // 模拟异步
    return new Promise((reslove, reject) => {
      setTimeout(() => {
        filePath = `temp_${filePath}`
        reslove(filePath)
      }, 1000)
    })
  }
})