element-ui tree 异步树实现勾选自动展开、指定展开、指定勾选功能

<el-tree
        :props="mulprops"
        :load="loadNode"
        lazy
        node-key="id"
        show-checkbox
        accordion
        @current-change="currentChange"
        :filter-node-method="filterNode"
        @check="handleCheck"
        ref="tree"
        :default-checked-keys="defaultCheckedNodes"
        :default-expanded-keys="defaultExpandedNodes"
    >
    </el-tree>

handleCheck(nodeData,  treeChecked) {
      let node = this.$refs.tree.getNode(nodeData.id)
      //将选中的未展开的节点进行展开
      if(node.checked && !node.expanded){
        node.expand(function(){
          for(let i=0; i< node.childNodes.length; i++){
            node.childNodes[i].expand()
          }
        })
      }
    }

<el-tree
        :props="mulprops"
        :load="loadNode"
        lazy
        node-key="id"
        show-checkbox
        accordion
        @check-change="handleCheckChange"
        :filter-node-method="filterNode"
        ref="tree"
        :default-checked-keys="defaultCheckedNodes"
        :default-expanded-keys="defaultExpandedNodes"
    >
    </el-tree>

handleCheckChange(nodeData, nodeSelected) {
      let tree = this.$refs.tree;
      let node = tree.getNode(nodeData.id)

      //展开选中的未展开的节点
      this.expandCheckedNotExpandNodes(node);

      //具体业务实现
      console.log(nodeData, nodeSelected)
    },
    //展开选中的未展开的节点
    expandCheckedNotExpandNodes(node) {
      let tree = this.$refs.tree;
      if (node.checked && !node.expanded && !node.isLeaf) {
        node.expand(function () {
          let childNodes = node.childNodes;
          for (let i = 0; i < childNodes.length; i++) {
            let childNode = childNodes[i];
            //手动触发check-change事件，事件处理函数中回继续调用此函数，形成递归展开
            tree.$emit('check-change', childNode.data, childNode.checked, childNode.indeterminate);
          }
        })
      }
    },

 <el-input type="text" v-model='nodeDataIds' placeholder="请输入结点数据ID(多个以逗号分割)"> ></el-input>
    <el-button type="primary" @click="expandNodes(nodeDataIds.split(','))">展开指定结点</el-button>

//展开匹配的结点，根结点默认展开
    expandNodes(nodeDataIds){
        let that = this;
        let tree = this.$refs.tree;
        let rootNode = tree.root;
        this.expandNode(rootNode, nodeDataIds);
    },
    //展开指定结点下匹配的结点
    expandNode(node, nodeDataIds){
        let that = this;
        //当前结点需要展开未展开，则展开(根结点默认展开)
        if(node.level==0 || nodeDataIds.indexOf(node.data.id) != -1){
           //展开孩子结点
           let expandChildren = function(){
               let childNodes = node.childNodes;
               for (let i = 0; i < childNodes.length; i++) {
                  let childNode = childNodes[i];
                  //递归展开孩子结点
                  that.expandNode(childNode, nodeDataIds);
               }
           }
           if(!node.expanded){
               //当前结点未展开则先展开，展开后再展开孩子结点
               node.expand(function(){
                    expandChildren();
               });
           }else{
                //当前结点已展开，直接展开孩子结点
                expandChildren();
           }
        }
    },

  <el-button type="primary" @click="checkNodes(nodeDataIds.split(','))">选中指定结点</el-button>

expandNodes(nodeDataIds)
展开完成的时机比较难判断
 checkNodes(nodeDataIds){
         let tree = this.$refs.tree;
         tree.setCheckedKeys(nodeDataIds, false)
    }

default-checked-keys=['node001','node002']

expandNodes(nodeDataIds)

//展开匹配的结点，根结点默认展开
    expandNodes(nodeDataIds){
        let that = this;
        let tree = this.$refs.tree;
        let rootNode = tree.root;
        this.expandNode(rootNode, nodeDataIds, function(){
            that.checkNodes(['node001','node002']);
        });
    },
    //展开指定结点下匹配的结点
    expandNode(node, nodeDataIds, callback){
        let that = this;
        //递归进入
        that.recursiveEnter();

        //当前结点需要展开未展开，则展开(根结点默认展开)
        if(node.level==0 || nodeDataIds.indexOf(node.data.id) != -1){
           //展开孩子结点
           let expandChildren = function(){
               let childNodes = node.childNodes;
               if(childNodes.length > 0){
                   for (let i = 0; i < childNodes.length; i++) {
                      let childNode = childNodes[i];
                      //递归展开孩子结点
                      that.expandNode(childNode, nodeDataIds, callback);
                   }
               }
           }
           if(!node.expanded){
               //当前结点未展开则先展开，展开后再展开孩子结点
               node.expand(function(){
                    //展开孩子结点
                    expandChildren();

                    //递归退出
                    that.recursiveExit(callback);
               });
           }else{
                //当前结点已展开，直接展开孩子结点
                expandChildren();

                //递归退出
                that.recursiveExit(callback);
           }
        }else{
            //递归退出
            that.recursiveExit(callback);
        }
    },
    //递归计入计数剩余递归次数
    recursiveEnter(){
        this.recursiveRemainCount++;
        console.log('enter recursiveRemainCount', this.recursiveRemainCount)
    },
    //递归退出计数剩余递归次数
    recursiveExit(callback){
       this.recursiveRemainCount--;
       console.log('exit recursiveRemainCount', this.recursiveRemainCount)
       if(this.recursiveRemainCount==0){
         if(callback){
            callback();
         }
       }
    },
    checkNodes(nodeDataIds){
         let tree = this.$refs.tree;
         tree.setCheckedKeys(nodeDataIds, false)
    }