因为:after-read="beforeRead"写错了，应该是after-read，文件读取完成后的回调函数，但是我刚开始写成了before-read，这是（文件读取前的回调函数，返回 false 可终止文件读取，支持返Promise）vant组件里面的，搞了好半天才出来。一定要细心。

<div class="uploderloding">
    <label for="">上传附件：</label>
    <van-uploader accept="image/*,.pdf,.doc.,rar,.zip,.docx" v-model="fileList" :after-read="beforeRead">
        <van-button icon="upgrade" type="default">上传文件</van-button>
    </van-uploader>
    <pcss"> style="margin-left: 5.4em;">支持扩展名：.rar .zip .doc .docx .pdf .jpg...</p>     
</div>

beforeRead (file,detail) {
  const abcd = file.abc = 1
  console.log(file,'detail',detail)
  if (abcd == 1) {
     file.status = 'uploading';
     file.message = '上传中...';
     setTimeout(() => {
        file.status = 'done';
        file.message = '上传成功';
        vant.Toast(file.message);
      }, 1000);
      clearTimeout()
  }else{
     file.status = 'uploading';
     file.message = '上传中...';
     setTimeout(() => {
        file.status = 'failed';
        file.message = '上传失败';
      }, 1000);
  }
  // return file,detail;
},