在外层包一层div

<div v-if="commodDialogForm">
      <el-dialog
        :before-close="handleDialogClose"
        :visible.sync="commodDialogForm"
        title=""
        center
        :append-to-body='true'
        :lock-scroll="false">
        <commod @commodData="commodData" @close="closeCommodDialog"></commod>
      </el-dialog>
    </div>