vue 四级联动效果

实现前提

首先看下，我们的开发环境及数据封装特点：
第一： 开发框架vue-cli3 elementUI
第二： 数据封装情况，详见代码部分 data中的 data;
满足以上2点再继续，如果数据封装有所不同，可根据实际情况稍作修改。

实现过程

此处主要采用vue计算属性以及watch监听输入框变化，展示不同的数据。只需加载时一次请求即可。

仅个人想法，如有更好的方法，欢迎指导交流;-)；

//html部分
<el-form :model="queryParams" ref="queryForm" :inline="true" label-width="80px">
      <el-form-item label="单元号" prop="propName">
        <el-select v-model="queryParams.propName" placeholder="请选择区域属性" clearable size="small" style="width: 140px"
          @keyup.enter.native="handleQuery">
          <el-option v-for="dict in propsOptions" :label="dict.name" :value="dict.name"/>
        </el-select>
      </el-form-item>
      <el-form-item label="" label-width="4px" prop="areaName">
        <el-select v-model="queryParams.areaName" placeholder="小区名称" clearable size="small" style="width: 110px"
                   @keyup.enter.native="handleQuery">
          <el-option v-for="dict in areaOptions" :label="dict.area" :value="dict.area"/>
        </el-select>
      </el-form-item>
      <el-form-item label="" label-width="4px" prop="buildingName">
        <el-select v-model="queryParams.buildingName" placeholder="楼号" clearable size="small" style="width: 110px"
                   @keyup.enter.native="handleQuery">
          <el-option v-for="dict in buildingsOptions" :label="dict.buildingNameTest" :value="dict.buildingName"/>
        </el-select>
      </el-form-item>
      <el-form-item label="" label-width="4px" prop="unit">
        <el-select v-model="queryParams.unit" placeholder="单元号" clearable size="small" style="width: 110px"
                   @keyup.enter.native="handleQuery">
          <el-option v-for="dict in unitsOptions" :label="dict.unitName" :value="dict.unit"/>
        </el-select>
      </el-form-item>      
    </el-form>
//js部分，
data(){
	return{
	// 查询参数
      queryParams: {
        pageNum: 1,
        pageSize: 10,
        buildingId: undefined,
        propName: undefined,
        areaName: undefined,
        buildingName: undefined,
        unit: undefined,
        roomNumber: undefined,
        address: undefined,
        acreage: undefined,
        deliveryTime: undefined,
        status: undefined,
      },
      //房屋地址联动数据
      listAll: [],//总数据
      propsOptions: [],//一级下拉数据
      areaOptions: [],//二级下拉数据
      buildingsOptions: [],//三级下拉数据
      unitsOptions: [],//四级下拉数据
      //房屋数据
	  data: {"公寓":
			   	{"清波园":{
				 "1":{
					"1":[{
						"buildingPropId":16,
						"prop":"公寓",
						"buildingAreaId":16,
						"area":"清波园",
						"buildingId":1,
						"buildingName":"1",
						"buildingUnitId":12,
						"unit":"1"}],
					"2":[{
						"buildingPropId":16,
						"prop":"公寓",
						"buildingAreaId":16,
						"area":"清波园",
						"buildingId":1,
						"buildingName":"1",
						"buildingUnitId":13,
						"unit":"2"}],
					"3":[{
						"buildingPropId":16,
						"prop":"公寓",
						"buildingAreaId":16,
						"area":"清波园",
						"buildingId":1,
						"buildingName":"1",
						"buildingUnitId":14,
						"unit":"3"}],
					},//1单元
				},//1号楼
			},//晴波园
		}//公寓
	}//return	
},
//计算属性
computed: {
    searchNewPropName() {
      return this.queryParams.propName;
    },
    searchAreaName(){
      return this.queryParams.areaName;
    },
    searchBuilding(){
      return this.queryParams.buildingName;
    }
  },
  //数据监听
  watch:{
    searchNewPropName(val) {
      let areaOptions = Object.keys(this.listAll[val]).map(item => ({
          area: item
        })
      );
      this.areaOptions = areaOptions;
      if(this.areaOptions){
        this.queryParams.areaName = areaOptions[0].area;
      }
    },
    searchAreaName(val){
      let arr = this.listAll[this.queryParams.propName][val];
      let buildingsOptions = Object.keys(arr).map(item => ({
          buildingName: item,
          buildingNameTest: item+"号楼"
        })
      );
      this.buildingsOptions = buildingsOptions;
      if(this.buildingsOptions){
        this.queryParams.buildingName = buildingsOptions[0].buildingName;
      }
    },
    searchBuilding(val){
      let arr = this.listAll[this.queryParams.propName][this.queryParams.areaName][val];
      let unitsOptions = Object.keys(arr).map(item => ({
        unit: item,
        unitName: item+'单元',
        })
      );
      this.unitsOptions = unitsOptions;
      if(this.unitsOptions){
        this.queryParams.unit = unitsOptions[0].unit;
      }
    }
  },
created() {
    this.getPropAreaList();
 },
 methods： {
 	/** 请求数据列表,此处我们直接把请求好的数据放在了data里，各位宝宝自行按照你们的要求请求数据即可 */
    getPropAreaList() {
         this.listAll = this.data;
      });
    },
 }