父组件<template><div> <el-row> <Tree/> </el-row> <el-row> <Tree :handleNodeClick="handleNodeClick" /> </el-row></div><script>import Tree from './Tree'export default { components: { Tree }, methods: { handleNodeClick(data) { console.log('父组件', data, 'this', this); } },}</script>子组件<template><div > <el-tree :data="data" :props="defaultProps" @node-click="handleNodeClick"></el-tree></div></template><script>export default { props: { handleNodeClick: { type: Function, default (data) { // this为空 console.log('子组件', data, 'this', this) } } }}</script>上面的代码 在父组件不传handleNodeClick时，想要子组件使用default函数，但是访问不到this 要怎么办？