element-ui的upload组件的clearFiles方法的调用

element-ui使用中碰到的问题

<template>
    <div>
        <el-button @click="clearFiles">重新上传el-button>
        <el-upload ref="my-upload">
            <el-button type="primary">点击上传el-button>
        el-upload>
    div>
template>

<script>
    export default {
        data(){
            return {
        }
    },
    methods: {
        clearFiles () {
            this.$refs['my-upload'].clearFiles();
        }
    }
};