使用el-tree实现懒加载、请求接口的检索依次展开

首要条件： 要求后端返回检索后的文件夹id集合
主要通过这个属性去实现defaultExpandedKeys

    <el-button @click="search"> 开始检索 el-button>
    <el-tree :props="defaultProps" :data="treeData" lazy :load="loadNode" ref="tree"
      :defaultExpandedKeys="defaultExpandedKeys" node-key="id">
    el-tree>
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我们这里举例检索返回的数据为：[8, 9, 1, 4, 3, 6, 5]

并且造假数据，只要展开节点就会加载递增id的树节点，也就是1 -> 2, 3, 2 -> 4, 5 依次类推

所以未检索前的树状态如下：

点击检索之后

逻辑代码以及假数据代码:

    search() {
      this.defaultExpandedKeys = [8, 9, 1, 4, 3, 6, 5];
    },
    getTree() {
      return this.$refs.tree;
    },
    loadNode(node, resolve) {
      setTimeout(() => {
        if (node.level === 0) {
          resolve([{
            id: 1,
            label: '1',
            children: []
          }, {
            id: 2,
            label: '2',
            children: []
          }])
        }
        const data = [];
        this.fakeId++;
        data.push({
          id: this.fakeId,
          label: this.fakeId,
          children: [],
        })
        this.fakeId++;
        data.push({
          id: this.fakeId,
          label: this.fakeId,
          children: [],
        })
        resolve(data)
      }, 500);
    },
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所有代码：

APP.VUE

<template>
  <div id="app">
    <el-button @click="search"> 开始检索 el-button>
    <el-tree :props="defaultProps" :data="treeData" lazy :load="loadNode" ref="tree"
      :defaultExpandedKeys="defaultExpandedKeys" node-key="id">
    el-tree>
    
  div>
template>

<script>
export default {
  name: "app",
  data() {
    return {
      defaultProps: {
        children: 'children',
        label: 'label',
        isLeaf: false,
      },
      defaultExpandedKeys: [1],
      fakeId: 2,
      treeData: [],
    };
  },
  methods: {
    search() {
      this.defaultExpandedKeys = [8, 9, 1, 4, 3, 6, 5];
    },
    getTree() {
      return this.$refs.tree;
    },
    loadNode(node, resolve) {
      setTimeout(() => {
        if (node.level === 0) {
          resolve([{
            id: 1,
            label: '1',
            children: []
          }, {
            id: 2,
            label: '2',
            children: []
          }])
        }
        const data = [];
        this.fakeId++;
        data.push({
          id: this.fakeId,
          label: this.fakeId,
          children: [],
        })
        this.fakeId++;
        data.push({
          id: this.fakeId,
          label: this.fakeId,
          children: [],
        })
        resolve(data)
      }, 500);
    },
  },
}
script>

<style lang="scss"scoped>

style>

<style>
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}
style>

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