利用vue+elementUI设置省市县三级联动下拉列表框的详细过程

this.$http({
              method:"get",
              url:"https://restapi.amap.com/v3/config/district?parameters",
              params:{
                  key:"3a708a4ef5e3af28694b1c861985a5ce",
                  keyWords:"中国",
                  subdistrict:3
              }
}).then((res)=>{
       this.form.provinceList = res.data.districts[0].districts  /* 省*/
         /* 进行遍历赋值*/
         /* 市区和县区*/
       let newProvince = this.form.provinceList
       for(let i = 0; i < newProvince.length; i++){              /* 省级*/
           for(let j = 0; j < newProvince[i].districts.length; j++){       /* 市级*/
               let city = newProvince[i].districts[j].name
               this.CITY.push({id:j+1,name:city,code:i+1})
               for(let k = 0;k<newProvince[i].districts[j].districts.length; k++){/* 县级*/
                   let xian = newProvince[i].districts[j].districts[k].name
                    this.XIAN.push({id:k+1,name:xian,code:j+1,cityCountyName:city})
               }
           }
       }
       for(let m = 0; m < newProvince.length;m++){
           newProvince[m] = {...newProvince[m],...{code:m+1}}
       }
       this.form.provinceList = newProvince
})

provinceChange(that){
    // 根据选中省，匹配市
    let cityCode = 0
    let newCityArry = []
    this.form.provinceList.forEach((item,index)=>{
        if(item.name == that){
            cityCode = item.code
        }
    })
       // console.log(cityCode)
    if(cityCode){
        this.form.cityList = []
        this.CITY.forEach((item,index)=>{
            if(item.code == cityCode){
                this.form.cityList.push(item)
            }
        })  /* 市匹配成功*/
    }
},

cityChange(that){
                let countyCode = 0
                let cityname = ''
                let newCountyArry = []
                this.form.cityList.forEach((item,index)=>{
                    if(item.name == that){
                        countyCode = item.id
                        cityname = item.name
                    }
                })
                if(countyCode){
                    this.form.countyList = []
                    this.XIAN.forEach((item,index)=>{
                        if(item.code == countyCode && item.cityCountyName == cityname){
                            this.form.countyList.push(item)
                        }
                    })
                }
            },