注意：一定要寫上this.$nextTick 否則不生效

　　　　　　<el-tree ref="treeRef" :highlight-current="true" default-expand-all :data="architectureData" node-key="id" :current-node-key="currentNodekey" :props="defaultProps" @node-click="handleNodeClick" ></el-tree>

currentNodekey: "", //預設選中的節點樹


async treeByDept() {
      await treeByDept({}).then((res) 
 
=> {
        this.architectureData = res.data;
      
        if (this.architectureData.length > 0) {
          this.currentNodekey = this.architectureData[0].id;
          this.$nextTick(() => {
            this.$refs.treeRef.setCurrentKey(this.currentNodekey); //一定要加這個選中了否則樣式沒有出來
           });
          
        }
      });
    },



 

/*點選樹結構項的選中顏色*/ .el-tree--highlight-current.is-current.el-tree-node>.el-tree-node__content{ background-color:#99ccff!important; }