element UI upload组件上传附件格式限制方法

<el-upload
 :action="uploadurl"
 ref="upload"
 :multiple="false"
 :on-change="filechange"
 :before-upload="beforeupload"
 :on-success="handleavatarsuccess"
 :on-preview="file_click"
 class="upload-demo"
 list-type="text"
 accept=".jpg,.jpeg,.png,.gif,.bmp,.pdf,.jpg,.jpeg,.pbg,.gif,.bmp,.pdf"
 :file-list="uploadform.personfilelist"
 :auto-upload="false">
 <el-button size="small" type="primary">选择文件</el-button>
  <div slot="tip" class="el-upload__tip"><i class="el-icon-warning" style="color:red;margin-right:5px"></i>单个文件不超过5mb</div>
 </el-upload>

accept=".jpg,.jpeg,.png,.gif,.bmp,.pdf,.jpg,.jpeg,.pbg,.gif,.bmp,.pdf"
//accept支持上传文件格式