参考代码：
JQuery中国省市区街道三级、四级联动下拉菜单插件
（将代码中单纯的四级联动提取出来，对其中的bug进行了修正，并完善了一些不完美的地方）
先通过最终效果看一下功能：
代码如下：
- index.html:（注：请将代码中的jquery.min.js替换成你本地的jquery地址）
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>jQuery四级联动下拉菜单代码</title>
<script type="text/javascript" src="script/jquery.min.js"></script>
<script type="text/javascript" src="script/jquery.citys.js"></script>
</head>
<body>
<div id="demo3" class="citys">
<p>
<select name="province" id="province"></select>
<select name="city"></select>
<select name="area"></select>
<select name="town"></select>
</p>
</div>
<script type="text/javascript">
var selectedAddress = {'province':'', 'city':'', 'area':'', 'town':''};
var $town = $('select[name="town"]');
var clearTown = function(){
$town.hide().empty();
}
var townFormat = function(info){
clearTown();
if(info['code']%1e4&&info['code']<7e5){ //是否为“区”且不是港澳台地区
$.ajax({
url:'http://passer-by.com/data_location/town/'+info['code']+'.json',
dataType:'json',
success:function(town){
$town.show();
$town.append('<option value=""> - 街道、乡镇 - </option>');
for(i in town){
$town.append('<option value="'+i+'">'+town[i]+'</option>');
}
}
});
}
};
$('#demo3').citys({
onChange: function(info){
clearTown();
selectedAddress.province = info.province;
selectedAddress.city = info.city;
selectedAddress.area = info.area;
},
onAreaChange:function(info){
townFormat(info);
}
},function(api){
var info = api.getInfo();
townFormat(info);
});
$town.on('change', function(){
selectedAddress.town = $(this).find("option:selected").text();
});
console.log(selectedAddress); //输出最终选择的省、市、区县、街道
</script>
</body>
</html>
- jquery.cities.js:
;(function (factory) {
if (typeof define === "function" && (define.amd || define.cmd) && !jQuery) {
// AMD或CMD
define([ "jquery" ],factory);
} else if (typeof module === 'object' && module.exports) {
// Node/CommonJS
module.exports = function( root, jQuery ) {
if ( jQuery === undefined ) {
if ( typeof window !== 'undefined' ) {
jQuery = require('jquery');
} else {
jQuery = require('jquery')(root);
}
}
factory(jQuery);
return jQuery;
};
} else {
//Browser globals
factory(jQuery);
}
}(function ($) {
$.support.cors = true;
$.fn.citys = function(parameter,getApi) {
if(typeof parameter == 'function'){ //重载
getApi = parameter;
parameter = {};
}else{
parameter = parameter || {};
getApi = getApi||function(){};
}
var defaults = {
dataUrl:'http://passer-by.com/data_location/list.json', //数据库地址
dataType:'json', //数据库类型:'json'或'jsonp'
provinceField:'province', //省份字段名
cityField:'city', //城市字段名
areaField:'area', //地区字段名
valueType:'code', //下拉框值的类型,code行政区划代码,name地名
code:0, //地区编码
province:0, //省份,可以为地区编码或者名称
city:0, //城市,可以为地区编码或者名称
area:0, //地区,可以为地区编码或者名称
required: false, //是否必须选一个
nodata: 'hidden', //当无数据时的表现形式:'hidden'隐藏,'disabled'禁用,为空不做任何处理
onChange:function(){}, //地区切换时触发,回调函数传入地区数据
onAreaChange:function(){} //区县切换时触发
};
var options = $.extend({}, defaults, parameter);
return this.each(function() {
//对象定义
var _api = {};
var $this = $(this);
var $province = $this.find('select[name="'+options.provinceField+'"]'),
$city = $this.find('select[name="'+options.cityField+'"]'),
$area = $this.find('select[name="'+options.areaField+'"]');
$.ajax({
url:options.dataUrl,
type:'GET',
crossDomain: true,
dataType:options.dataType,
jsonpCallback:'jsonp_location',
success:function(data){
var province,city,area,hasCity;
if(options.code){ //如果设置地区编码，则忽略单独设置的信息
var c = options.code - options.code%1e4;
if(data[c]){
options.province = c;
}
c = options.code - (options.code%1e4 ? options.code%1e2 : options.code);
if(data[c]){
options.city = c;
}
c = options.code%1e2 ? options.code : 0;
if(data[c]){
options.area = c;
}
}
var updateData = function(){
province = {},city={},area={};
hasCity = false; //判断是非有地级城市
for(var code in data){
if(!(code%1e4)){ //获取所有的省级行政单位
province[code]=data[code];
if(options.required&&!options.province){
if(options.city&&!(options.city%1e4)){ //省未填，并判断为直辖市
options.province = options.city;
}else{
options.province = code;
}
}else if(data[code].indexOf(options.province)>-1){
options.province = isNaN(options.province)?code:options.province;
}
}else{
var p = code - options.province;
if(options.province&&p>0&&p<1e4){ //同省的城市或地区
if(!(code%100)){
hasCity = true;
city[code]=data[code];
if(data[code].indexOf(options.city)>-1){
options.city = isNaN(options.city)?code:options.city;
}
}else if(p>9000){ //省直辖县级行政单位
city[code] = data[code];
if(data[code].indexOf(options.city)>-1){
options.city = isNaN(options.city)?code:options.city;
}
}else if(hasCity){ //非直辖市
var c = code-options.city;
if(options.city&&c>0&&c<100){ //同个城市的地区
area[code]=data[code];
if(data[code].indexOf(options.area)>-1){
options.area = isNaN(options.area)?code:options.area;
}
}
}else{
area[code]=data[code]; //直辖市
if(data[code].indexOf(options.area)>-1){
options.area = isNaN(options.area)?code:options.area;
}
}
}
}
}
};
var format = {
province:function(){
$province.empty();
if(!options.required){
$province.append('<option value=""> - 所在省 - </option>');
}
for(var i in province){
$province.append('<option value="'+(options.valueType=='code'?i:province[i])+'" data-code="'+i+'">'+province[i]+'</option>');
}
if(options.province){
var value = options.valueType=='code'?options.province:province[options.province];
$province.val(value);
}
this.city();
},
city:function(){
$city.empty();
if(!hasCity){
$city.css('display','none');
}else{
$city.css('display','');
if(!options.required){
$city.append('<option value=""> - 所在市 - </option>');
}
if(options.nodata=='disabled'){
$city.prop('disabled',$.isEmptyObject(city));
}else if(options.nodata=='hidden'){
$city.css('display',$.isEmptyObject(city)?'none':'');
}
for(var i in city){
$city.append('<option value="'+(options.valueType=='code'?i:city[i])+'" data-code="'+i+'">'+city[i]+'</option>');
}
if(options.city){
var value = options.valueType=='code'?options.city:city[options.city];
$city.val(value);
}else if(options.area){
var value = options.valueType=='code'?options.area:city[options.area];
$city.val(value);
}
}
this.area();
},
area:function(){
$area.empty();
if(!options.required){
$area.append('<option value=""> - 所在区、县 - </option>');
}
if(options.nodata=='disabled'){
$area.prop('disabled',$.isEmptyObject(area));
}else if(options.nodata=='hidden'){
$area.css('display',$.isEmptyObject(area)?'none':'');
}
for(var i in area){
$area.append('<option value="'+(options.valueType=='code'?i:area[i])+'" data-code="'+i+'">'+area[i]+'</option>');
}
if(options.area){
var value = options.valueType=='code'?options.area:area[options.area];
$area.val(value);
}
}
};
//获取当前地理信息
_api.getInfo = function(){
var status = {
direct:!hasCity,
province:data[options.province]||'',
city:data[options.city]||'',
area:data[options.area]||'',
code:options.area||options.city||options.province
};
return status;
};
//事件绑定
$province.on('change',function(){
options.province = $(this).find('option:selected').data('code')||0; //选中节点的区划代码
options.city = 0;
options.area = 0;
updateData();
format.city();
options.onChange(_api.getInfo());
});
$city.on('change',function(){
options.city = $(this).find('option:selected').data('code')||0; //选中节点的区划代码
options.area = 0;
updateData();
format.area();
options.onChange(_api.getInfo());
});
$area.on('change',function(){
options.area = $(this).find('option:selected').data('code')||0; //选中节点的区划代码
options.onChange(_api.getInfo());
options.onAreaChange(_api.getInfo());
});
//初始化
updateData();
format.province();
if(options.code){
options.onChange(_api.getInfo());
}
getApi(_api);
}
});
});
};
}));