elementUI如何动态给el-tree添加子节点数据children详解

<el-tree
    ref="treeNav"
    :indent="10"
    :default-expanded-keys="defaultExpandedKeys"
    @node-click="treeNodeClicked"
    :data="treeData"
    :highlight-current="true"
    node-key="id">
</el-tree>

 this.defaultExpandedKeys = [nodeData.id]

        // 存在 projectId 时，加载对应项目的 preview 信息，并定位到之前的设备位置
        if (this.currentProjectId){
            this.getProjectPreviewOf(this.currentProjectId, projectPreview => {
                let checkedKey = `project-${this.currentProjectId}:${this.deviceName}`
                this.$refs.treeNav.setCurrentKey(checkedKey)
                this.SET_CURRENT_DEVICE_LIST(projectPreview[this.deviceName])
            })
        }

// 根据 projectId 获取对应项目的 preview
getProjectPreviewOf(nodeData){
    areaApi
        .previewOfProject({
            pid: nodeData.projectInfo.id
        })
        .then(res => {
            let treeDataForPreview = this.getTreeDataFromPreview(res, nodeData.projectInfo.id)
            console.log('Tree data for preview: ',treeDataForPreview)
            this.$refs.treeNav.updateKeyChildren(nodeData.id, treeDataForPreview)
            // 展开当前节点
            this.defaultExpandedKeys = [nodeData.id]
            // 默认展示：当前项目的第一个设备类型的设备
            this.SET_CURRENT_DEVICE_LIST(treeDataForPreview[0].deviceInfos)
        })
},

<template>
  <div>
    <el-tree
      :data="data"
      node-key="id"
      default-expand-all
      :expand-on-click-node="false"
      ref="tree"
    >
    <!-- v-show="data.swit" -->
      <span class="custom-tree-node" slot-scope="{ data }">
        <span>{{data.label }}</span>
        //根据data.show!=null是否等于null来判断显示与否
        <span v-if="data.show!=null"
          ><el-switch
           
            v-model="data.show"
            :active-value="true"
            :inactive-value="false"
            active-color="#13ce66"
            inactive-color="#ff4949"
          >
          </el-switch
        >{{data.show}}
        </span>
         <!--  -->
      </span>
    </el-tree>
    <el-button @click="handleNodeClick">获取</el-button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      form: {},
      // valuettt: false,

      data: [
        {
          label: "aaa",
          show: null,
          children: [
            {
              label: "aaa",
              show: null,//等于null不显示开关
              children: [
                {
                  label: "ccc",
                  show: null,
                  children: [
                    {
                      label: "ccc",
                      show: null,
                      children: [
                        {
                          label: "三级 3-1-1",
                          show: true,//等于true显示开关
                          children: [],
                        },
                      ],
                    },
                  ],
                },
                {
                  label: "eee",
                  show: null,
                  children: [
                    {
                      label: "三级 3-2-2",
                      show: true,
                      children: [],
                    },
                  ],
                },
              ],
            },
          ],
        },
        {
          label: "二级 3-2",
          show: null,
          children: [
            {
              label: "三级 3-2-1",
              show: true,
              children: [],
            },
          ],
        },
      ],
      defaultProps: {
        children: "children",
        label: "label",
      },
      result: [],
    };
  },
  methods: {
    handleNodeClick() {
      // this.$refs.tree.updateKeyChildren(keys,treeData)//更新node-key的子节点
      this.getAllLeaf(this.data);
      // console.log(this.$refs.tree.getCheckedNodes(), "这是数据");
    },
    getAllLeaf(data) {
      let result = [];
      function getLeaf(data) {
        data.forEach((item) => {
          if (item.children.length == 0) {
            // console.log(item.label,'item.label');
            result.push(item.label);
          } else {
            // console.log(item.children,'item.children');
            getLeaf(item.children);
          }
        });
      }
      console.log(result, "data");
      getLeaf(data);
      this.result = result;
      return result;
    },
  },
  mounted(){
    this.handleNodeClick()
  }
};
</script>

<style>
/* .custom-tree-node {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 14px;
    padding-right: 8px;
  } */
</style>