本文实例讲述了js实现简单的省市县三级联动效果。分享给大家供大家参考，具体如下：
js代码部分
//省市县数据格式
var province_city_county_data=[
{
province:"四川",
city:[
{
cityName:"成都",
county:["成都市","崇州市","金堂县"]
},
{
cityName:"南充",
county:["仪陇县","南部县","营山县"]
}
]
},
{
province:"北京",
city:[
{ cityName:"北京市",
county:["东城区","朝阳区"]
}
]
},
{
province:"安徽",
city:[
{ cityName:"安庆",
county:["安庆市","怀宁县","潜山县"]
},
{ cityName:"蚌埠",
county:["蚌埠市","固镇县","怀远县"]
}
]
}
]
var opt0 = ["省份","地级市","市、县级市、县"];
var selectID_arr2=["provinceid","cityid","countyid"];
var province_index;
window.onload = function(){
//初始化下拉框
function init_select(){
init_title();
init_province();
bind_province();
}
//初始化提示标题
function init_title(){
for(var k = 0;k<selectID_arr2.length;k++){
var select_obj= document.getElementById(selectID_arr2[k]);
select_obj.options[0]=new Option(opt0[k],opt0[k]);
}
}
//初始化省份
function init_province(){
var province_select_obj = document.getElementById(selectID_arr2[0]);
var province_len = province_city_county_data.length;
for(var i = 0;i<province_len;i++){
province_select_obj.options[i+1] = new Option(province_city_county_data[i].province,province_city_county_data[i].province);
}
}
//给省份绑定onchange事件
function bind_province(){
var province_select_obj = document.getElementById(selectID_arr2[0]);
province_select_obj.onchange=function(){
var opt_index =province_select_obj.selectedIndex;
if(opt_index!=0){
province_index = opt_index-1; //每个省份的序号比 option 的下标要小1
init_city(province_index);
bind_city();
init_county(province_index,0);
}else{
clear_city();
clear_county();
}
}
}
//选择一个省份才能初始化地级市
function init_city(index){
clear_city();
var city_len = province_city_county_data[index].city.length;
for(var i = 0;i<city_len;i++){
document.getElementById(selectID_arr2[1]).options[i+1] = new Option(province_city_county_data[index].city[i].cityName,province_city_county_data[index].city[i].cityName);
}
document.getElementById(selectID_arr2[1]).options[1].selected = true;
}
//清除地级市信息
function clear_city(){
var city_select_obj = document.getElementById(selectID_arr2[1]);
city_select_obj.options.length=0; //每次选中一个新的省份 都重新删除地级市的信息
init_title(); //重新初始化标题
}
//给地级市绑定onchange事件
function bind_city(){
var city_select_obj = document.getElementById(selectID_arr2[1]);
city_select_obj.onchange=function(){
var opt_index =city_select_obj.selectedIndex;
if(opt_index!=0){
init_county(province_index,opt_index-1);
}else{
clear_county();
}
}
}
//选择一个地级市后才能初始化县
function init_county(index,city_index){
clear_county();
var county_len = province_city_county_data[index].city[city_index].county.length;
for(var i = 0;i<county_len;i++){
document.getElementById(selectID_arr2[2]).options[i+1] = new Option(province_city_county_data[index].city[city_index].county[i],province_city_county_data[index].city[city_index].county[i]);
}
document.getElementById(selectID_arr2[2]).options[1].selected = true;
}
//清除县城信息
function clear_county(){
var county_select_obj = document.getElementById(selectID_arr2[2]);
county_select_obj.options.length=0; //每次选中一个新的地级市 都重新删除县的信息
init_title(); //重新初始化标题
}
init_select()
}
html部分
<select id="provinceid"></select> <select id="cityid"></select> <select id="countyid"></select>
更多关于JavaScript相关内容感兴趣的读者可查看本站专题：《JavaScript中json操作技巧总结》、《JavaScript动画特效与技巧汇总》、《JavaScript扩展技巧总结》、《JavaScript运动效果与技巧汇总》、《JavaScript数学运算用法总结》及《javascript面向对象入门教程》
希望本文所述对大家JavaScript程序设计有所帮助。
