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