微信小程序如何实现多图上传及预览删除

fileList: [], 
newArr:[] ,
arr:[],

 <view style="margin-top: 15px;margin-left: 10px;">
      <van-uploader file-list="{{ fileList }}" preview-full-image="true" multiple="true" preview-image="true" max-count="3" bind:after-read="afterRead" bind:delete="del" />
 </view>

afterRead(event){
   console.log(event);
   var img = event.detail.file;
   let that = this;
   let arr = this.data.newArr
   that.setData({
       arr:img
    })
    console.log(img);
   img.map(function(v){
     let imgs = v.url;
     console.log(imgs);
       wx.uploadFile({ 
       filePath: imgs, 
       name: 'file', 
       url: '你的接口',
       success(res){
         let aa = JSON.parse(res.data)
         let img = aa.front_file
         console.log(img);
         arr.push({url:'接口前缀'+img});
         that.setData({
          fileList:arr 
         })
         console.log(that.data.fileList);
         console.log(that.data.newArr);
       }
     })
   })
  },

del(event){
    let id = event.detail.index
    let newArr = this.data.newArr
    let fileList = this.data.fileList
    newArr.splice(id,1) 
    fileList.splice(id,1)
    console.log(this.data.fileList);
    this.setData({
      fileList:fileList, 
      newArr:newArr
    })
 },