美文网首页
js原生实现省市两级联动

js原生实现省市两级联动

作者: Light_shallow | 来源:发表于2018-12-10 22:46 被阅读0次

因为引Jquery太麻烦了,尝试用原生写一个关于省级联动这种类似功能的。

实现效果

这里想要的效果是如果选择省份,自动出现省份对应的城市 

首先,后台返回的数据结构是这样子的

然后,我要把这些需要展示联动的关键字剥离开来,在这儿就是cityName,和它的store里面的address

result.map(item=>{

                        city.push({label:item.cityName,store:item.store});

                    })

                    city.map((item,index) =>{

                        var city = item.label;

                        temp = [];

                        if(item.store.length > 1){

                            item.store.map((item,index)=>{

                                temp.push(item.shopName);

                            })

                            area[city] = temp;

                        }else {

                            area[city] = [item.store[0].shopName];

                        }   

                    })  

                    console.log(area);

把这些数据处理完之后,出现这样的效果

接下来,html结构

<select id="selProvince" onchange="changeCity()">

  <option>请选择省份</option>

</select>

<select id="selCity">

  <option>请选择城市</option>

</select>

第一,这个是为了更简单的写语句,类似于Jquery的写法

function $(ID){ 

        return document.getElementById(ID);

    } // 

第二步,把整理好的数据,塞到各个option里面

    var province = $("selProvince");

                    for (var i in area) {

                        province.add(new Option(i,i),null);

                    }   

第三,动态响应,触发onchange事件,选择哪个,就出来相对应的option

    function changeCity(){

            var province = $("selProvince").value;

            var city = $("selCity");

            city.options.length = 0;

            for (var i in area) {

                if(i == province){

                    for (var j in area[i]) {

                        city.add(new Option(area[i][j],area[i][j]),null);

                    }

                }

            }

        }

其中用到两个知识点

一、add(),引用官方解释

定义和用法

add() 方法用于向 <select> 添加一个 <option> 元素。

语法

selectObject.add(option,before)

参数描述

option必需。要添加选项元素。必需是 option 或 optgroup 元素。

before必需。在选项数组的该元素之前增加新的元素。如果该参数是null,元素添加到选项数组的末尾。

二、new option(); 一般用在动态生成选择项目

new Option("显示的文本labe","值value",true,true)

后面两个true分别表示默认被选中和有效!,可写可不写

最后文章的末尾放上所有代码 :

<!DOCTYPE html>

<html lang="zh">

<head>

    <meta charset="UTF-8">

    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">

    <meta name="viewport" content="width=device-width, initial-scale=1.0">

    <title>title</title>

</head>

<body>

<select id="selProvince" onchange="changeCity()">

  <option>请选择省份</option>

</select>

<select id="selCity">

  <option>请选择城市</option>

</select>

<script >

    window.onload = function(){

        if(window.XMLHttpRequest){

            var oAjax = new XMLHttpRequest();//创建ajax对象

        }else {

            var oAjax = new ActiveXObject("Microsoft.XMLHTTP");

        }

        oAjax.open("Post","XXXXXX请求的接口地址",true); 

        oAjax.send();

        oAjax.onreadystatechange = function(){

            if(oAjax.readyState == 4) {

                if(oAjax.status == 200){     

                    result = JSON.parse(oAjax.responseText).resultData.result_org;

                    city= [];

                    area = [];

                    result.map(item=>{

                        city.push({label:item.cityName,store:item.store});

                    })

                    city.map((item,index) =>{

                        var city = item.label;

                        temp = [];

                        if(item.store.length > 1){

                            item.store.map((item,index)=>{

                                temp.push(item.shopName);

                            })

                            area[city] = temp;

                        }else {

                            area[city] = [item.store[0].shopName];

                        }   

                    })  

                    var province = $("selProvince");

                    for (var i in area) {

                        province.add(new Option(i,i),null);

                    }   

                }else{

                    console.log("失败");

                }

            }

        };

    }

    function $(ID){ 

        return document.getElementById(ID);

    }

    function changeCity(){

            var province = $("selProvince").value;

            var city = $("selCity");

            city.options.length = 0;

            for (var i in area) {

                if(i == province){

                    for (var j in area[i]) {

                        city.add(new Option(area[i][j],area[i][j]),null);

                    }

                }

            }

    }

</script>

</body>

</html>

相关文章

网友评论

      本文标题:js原生实现省市两级联动

      本文链接:https://www.haomeiwen.com/subject/wwxjhqtx.html