vue+element树组件 实现树懒加载

 本文连接 https://www.cnblogs.com/aknife/p/11709255.html

一.页面样式

二.数据库

 三.前端页面代码

<template>

  <el-tree :props="props"
           :load="loadNode"
           lazy
           show-checkbox>
  </el-tree>

</template>
<script>
export default {
  data () {
    return {
      props: {
        label: 'name',
        children: 'zones',
        isLeaf: 'leaf',

      },
    };
  },
  methods: {
    loadNode (node, resolve) {
      //如果展开第一级节点，从后台加载一级节点列表
      if (node.level == 0) {
        this.loadfirstnode(resolve);
      }
      //如果展开其他级节点，动态从后台加载下一级节点列表
      if (node.level >= 1) {
        this.loadchildnode(node, resolve);
      }
    },
    //加载第一级节点
    loadfirstnode (resolve) {

      this.api({
        url: "/test/tree",
        method: "post",

      }).then(data => {
        console.log(data);
        //this.data = data.list;
        return resolve(data.list);

      })
    },
    //加载节点的子节点集合
    loadchildnode (node, resolve) {
      this.api({
        url: "/test/tree2",
        method: "post",
        params: {
          id: node.data.id
        }
      }).then(data => {
        console.log(data);
        //this.defaultProps.children = data.list;
        return resolve(data.list);

      })
    }

  }

}
</script>

controller层

    @PostMapping("/tree")
    public JSONObject tree( ) {return userService.tree();
    }

    @PostMapping("/tree2")
    public JSONObject tree(@RequestParam Map<String, Object> user) {return userService.tree2(user);
    }

service层

    /**
     * 树
     */
    JSONObject tree();
    
    /**
     * 树
     */
    JSONObject tree2(Map<String, Object> user);

serviceImpl层

    @Override
    public JSONObject tree() {
        List<JSONObject> list=userDao.tree();
        System.out.println(list);
        return CommonUtil.successPage(list);
    }
    
    @Override
    public JSONObject tree2(Map<String, Object> user) {
        int codept=Integer.parseInt(user.get("id").toString()) ;
        List<JSONObject> list=userDao.tree2(codept);
        return CommonUtil.successPage(list);
    }

dao层

    /**
     * 树
     */
    List<JSONObject> tree();
    List<JSONObject> tree2(@Param("codept")int codept);

mapper层

    <select id="tree" resultType="com.alibaba.fastjson.JSONObject">
     SELECT [id]
      ,[codept]
      ,[name]
  FROM [dbo].[Dept] WHERE codept ='0'
    </select>

   <select id="tree2" resultType="com.alibaba.fastjson.JSONObject">
     SELECT [id]
      ,[codept]
      ,[name]
  FROM [dbo].[Dept] WHERE codept =#{codept}
    </select>

本文连接https://www.cnblogs.com/aknife/p/11709255.html