基本思想就是：在JS动态创建select控件的option,通过Ajax获取在PHP从SQL数据库获取的省市区信息，代码有点长，但很多都是类似的，例如JS中省、市、区获取方法类似，PHP中通过参数不同执行不同的select语句。
index.html代码：
复制代码 代码如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>省市区三级联动</title>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<script src="https://www.jb51.net/scripts/thumbnails.js" type="text/javascript"></script>
</head>
<body>
<div>
<select onchange="sech(this.id)">
<option value="province">请选择省份</option>
</select>
<select onchange="sech(this.id)">
<option value="city">请选择市区</option>
</select>
<select>
<option value="county">请选择县乡</option>
</select>
</div>
</div>
</body>
</html>
thumbnails.js代码：
复制代码 代码如下:
window.onload = getProvince;
function createRequest() {//Ajax于PHP交互需要对象
try {
request = new XMLHttpRequest();//创建一个新的请求对象;
} catch (tryMS) {
try {
request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (otherMS) {
try {
request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (failed) {
request = null;
}
}
}
return request;
}
function sech(id) {//省市改变时触发，select的onchange事件
var aa = document.getElementById(id);
if(id=="sheng"){
getCity(aa.value);//这里aa.value为省的id
}
if(id=="shi")
{
getCounty(aa.value);//这里aa.value为市的id
}
}
function getProvince() {//获取所有省
request = createRequest();
if (request == null) {
alert("Unable to create request");
return;
}
var url= "getDetails.php?ID=0";//ID=0时传递至PHP时让其获取所有省
request.open("GET", url, true);
request.onreadystatechange = displayProvince; //设置回调函数
request.send(null); //发送请求
}
function getCity(id){//获取省对应的市
request = createRequest();
if (request == null) {
alert("Unable to create request");
return;
}
var url= "getDetails.php?ID=" + escape(id);
request.open("GET", url, true);
request.onreadystatechange = displayCity;
request.send(null);
}
function getCounty(id){//获取市对应的区
request = createRequest();
if (request == null) {
alert("Unable to create request");
return;
}
var url= "getDetails.php?ID=" + escape(id);
request.open("GET", url, true);
request.onreadystatechange = displayCounty;
request.send(null);
}
function displayProvince() {//将获取的数据动态增加至select
if (request.readyState == 4) {
if (request.status == 200) {
var a=new Array;
var b=request.responseText;//将PHP返回的数据赋值给b
a=b.split(",");//通过","将这一数据保存在数组a中
document.getElementById("sheng").length=1;
var obj=document.getElementById("sheng');
for(i=0;i
obj.options.add(new Option(a[i],i+1)); //动态生成OPTION加到select中，第一个参数为Text,第二个参数为Value值.
}
}
}
function displayCity() {//将获取的数据动态增加至select
if (request.readyState == 4) {
if (request.status == 200) {
var a=new Array;
var b=request.responseText;
a=b.split(",");
document.getElementById("shi").length=1;//重新选择
document.getElementById("xian").length=1;//重新选择
if(document.getElementById("sheng").value!="province"){
var obj=document.getElementById('shi');
for(i=0;i
obj.options.add(new Option(a[i], document.getElementById("sheng").value*100+i+1)); //ocument.getElementById("sheng").value*100+i+1对应的是市的ID。
}
}
}
}
function displayCounty() {//将获取的数据增加至select
if (request.readyState == 4) {
if (request.status == 200) {
var a=new Array;
var b=request.responseText;
a=b.split(",");
document.getElementById("xian").length=1;
if(document.getElementById("sheng").value!="province"&&document.getElementById("shi").value!="city"){
var obj=document.getElementById('xian');
for(i=0;i
obj.options.add(new Option(a[i],i+1001));
}
}
}
}
getDetails.php代码：
复制代码 代码如下: