具体代码

html

<el-tree
    style="width: 100%"
    ref="treeRef"
    :data="roleTreedata"
    show-checkbox
    :expand-on-click-node="false"
    :check-strictly="!isParentchildLinkage"
    :props="defaultProps"
    node-key="id"
/>

js

import {  ElTree } from "element-plus";
const treeRef = ref<InstanceType<typeof ElTree>>();
const expandBtn = (e: boolean) => {
	const allNodes = treeRef.value!.store._getAllNodes();
	allNodes.forEach((item, index) => {
		item.expanded = e;
	});
};