vue2 + echats树状图 点击按钮 展开所有节点/收起所有节点

<template><div><button @click="expandAll(isExpanded)">{{ isExpanded ? '一键收起' : '一键展开' }}</button><div ref="echartsTree" style="width: 600px; height: 400px;"></div></div>
</template><script>
import * as echarts from 'echarts';export default {data() {return {isExpanded: true,myChart: null,option: {}};},methods: {getList() {this.option = {series: [{type: 'tree',data: [{name: 'root',children: [{ name: 'child1' },{ name: 'child2', children: [{ name: 'grandchild1' }] }]}],expandAndCollapse: true // 开启节点展开折叠}]}},// 一键展开expandAll(e) {if (e == false) {this.handleClose();this.isExpanded = !e;} else {this.option.series = {type: 'tree',data: [{name: 'root'}]}this.myChart.setOption(this.option);this.isExpanded = !e;}},// 一键关闭handleClose() {this.getList();this.myChart.setOption(this.option);},initChart() {this.myChart = echarts.init(this.$refs.echartsTree);this.myChart.setOption(this.option);}},mounted() {this.getList();this.$nextTick(() => {this.initChart()})}
};
</script>