1. data: {data: {
  images: []
},
upload: function(){
  wx.chooseImage({
    count: 1,//数量为1个
    sizeType: ['original', 'compressed'],//选择原图或压缩后的图片
    sourceType: ['album', 'camera'],//选择访问相册、相机
    success(res) {
      // tempFilePath可以作为img标签的src属性显示图片
      const tempFilePaths = res.tempFilePaths
      wx.cloud.uploadFile({
        cloudPath: new Date().getTime() + '.png',
        filePath: tempFilePaths[0], // 文件路径是数组，取第一个
        success: res => {
          // get resource ID
          db.collection('images').add({
            data:{
              fileID: res.fileID
            }
          }).then(res => {
            console.log(res);
          }).catch(err => {
            console.log(err)
          })
        },
        fail: err => {
          // handle error
        }
      })
    }
  })
},

<block wx:for='{{images}}'>
  <image src='{{item.fileID}}'></image>
  <button size='mini' data-fileid='{{item.fileID}}' bindtap='downloadFile'>文件下载</button>
</block>

downloadFile: function(e){
  wx.cloud.downloadFile({
    fileID: e.target.dataset.fileid,
  }).then(res => {
    // get temp file path
    //保存图片到手机相册
    wx.saveImageToPhotosAlbum({
      filePath: res.tempFilePath,
      success(res) { 
        wx.showToast({
          title: '保存成功',
        })
      }
    })
  }).catch(error => {
    // handle error
  })
},
2.

<button bindtap='getFile'>文件展示</button>
<block wx:for='{{images}}'>
  <image src='{{item.fileID}}'></image>
</block>

1. getFgetFile: function(){
  //使用云函数获取openid
  wx.cloud.callFunction({
    name: 'login'
  }).then(res=>{
    db.collection('images').where({
      _openid: res.result.openid
    }).get().then(res2=>{
      console.log(res2);
      this.setData({
        images: res2.data
      })
    })
  })
},