van-uploader uploads images, and cannot preview the image using base64 echo

1.今天在开发过程中,遇到了使用vant上传组件,The echo cannot be previewed,在搜索后,解决方法如下：

• html：

 <van-uploader v-model="fileList"
               accept='.jpg,.jpeg,.png'
               :before-read="beforeRead"
               :after-read="afterRead"
               :max-size="10000 * 1024"
               @oversize="onOversize"
               :before-delete="beforeDel" />

• js

        fileNameList.split(',').forEach(v => {
    // Iterate over the filenames returned by the backend
          this.$http.secondParty.getImageByName({
     fileName: v }).then(k => {
    
          // filename request tobase64格式文件
            // 图片base64转url
            let img = 'data:image/jpeg;base64,' + k.data
            let imgurl = this.base64ImgtoFile(img)
            console.log('imgurl===', imgurl)
            let url =
              window.webkitURL.createObjectURL(imgurl) ||
              window.URL.createObjectURL(imgurl)
            // 创建图片地址
            this.fileList.push({
    
              content: 'data:image/jpeg;base64,' + k.data,
              File: imgurl,
              name: v,
              status: 'done',
              message: '上传中',
              isImage: true,
              url
            })
          })
        })

• base64转文件

  base64ImgtoFile(dataurl, filename = 'file') {
    
      const arr = dataurl.split(',')
      const mime = arr[0].match(/:(.*?);/)[1]
      const suffix = mime.split('/')[1]
      const bstr = atob(arr[1])
      let n = bstr.length
      const u8arr = new Uint8Array(n)
      while (n--) {
    
        u8arr[n] = bstr.charCodeAt(n)
      }
      return new File([u8arr], `${
      filename}.${
      suffix}`, {
    
        type: mime
      })
    },