这篇文章主要介绍了jquery+asp.net实现省市二级联动功能的方法,涉及asp.net数据库读取与字符串转换相关操作技巧,需要的朋友可以参考下
本文实例讲述了jquery+asp.net实现省市二级联动功能的方法。分享给大家供大家参考，具体如下：
页面html:
<%@ page language="c#" autoeventwireup="true" codefile="ddlajax.aspx.cs" inherits="threeajaxdrop_ddlajax" %>
<!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 runat="server">
<title>dropdownlist三级联动</title>
<style type="text/css">
*{margin:0; padding:0;}
body{font-size:12px; font-family:arial @宋体;}
</style>
<script type="text/javascript" src="../js/jquery-1.4.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
//加载完成后绑定省份数据
$.getjson("default.aspx", function(data) { //data的数据格式[{"text":"北京","value":"0001"},{"text":"江西","value":"0031"}]
//alert(data[0].text+"|"+data[0].value);
$.each(data, function(index, value) {
//alert(value.text + "|" + value.value);
$("#selprovince").append("<option value='" + value.value + "'>" + value.text + "</option>");
});
});
//省份的值改变，则要绑定出城市下拉框
$("#selprovince").change(function(){
document.getelementbyid("selarea").options.length=1; //先清掉县下拉框的的数据
document.getelementbyid("selcity").options.length=1; //先清掉城市下拉框的的数据
$.getjson("handlerdropdownajax.ashx",{"type":"city","fid":$(this).val()},function(data){
$.each(data, function(index, value) {
$("#selcity").append("<option value='" + value.value + "'>" + value.text + "</option>");
});
});
});
//城市下拉框的值改变
$("#selcity").change(function(){
document.getelementbyid("selarea").options.length=1; //先清掉县下拉框的的数据
$.getjson("handlerdropdownajax.ashx",{"type":"area","fid":$(this).val()},function(data){
$.each(data, function(index, value) {
$("#selarea").append("<option value='" + value.value + "'>" + value.text + "</option>");
});
});
});
});
</script>
</head>
<body>
<form id="form1" runat="server">
<p>
三级联动：<select id="selprovince">
<option value="选择省份">==选择省份==</option>
</select> <select id="selcity"><option>==选择城市==</option></select>& amp;nbsp; <select id="selarea"><option>==选择县==</option></select>
</p>
</form>
</body>
</html>
asp.net部分:
(1)default.aspx.cs
public partial class threeajaxdrop_default : system.web.ui.page
{
protected void page_load(object sender, eventargs e)
{
string sql = "select * from province";
string strtemp = "\"text\":\"{0}\",\"value\":\"{1}\""; //构造格式字符串 {"text":"北京","value":"00001"}
stringbuilder sb = new stringbuilder();
oledbdatareader reader = oledbhelper.executereader(sql);
while (reader.read())
{
string str1 = string.format(strtemp, reader["province"].tostring(), reader["provinceid"].tostring());
sb.append("{"+str1+"},");
}
reader.close();
string json = sb.tostring();
response.write("["+json.substring(0,json.length-1)+"]");
}
}
(2)handlerdropdownajax.ashx
public class handlerdropdownajax : ihttphandler {
public void processrequest (httpcontext context) {
if (context.request.querystring["type"] != null && context.request.querystring["fid"] != null)
{
string type = context.request.querystring["type"].tostring(); //主要用于识别是查询city还是area表
string fid = context.request.querystring["fid"].tostring(); //城市或区域的父id
string sql = "select * from " + type + " where father='" + fid + "'";
//构造数据的类型[{"text":"南昌","value":"0001"},{"text":"上饶","value":"0002"}]
//string strtemp = "{\"text\":\"{0}\",\"value\":\"{1}\"}";//这里犯了个错误：直接这样构造会出错，因为大括号里又有格式大括号，解析会出错
string strtemp = "\"text\":\"{0}\",\"value\":\"{1}\""; //构造格式字符串 {"text":"北京","value":"00001"}
stringbuilder sb = new stringbuilder();
oledbdatareader reader = oledbhelper.executereader(sql);
while (reader.read())
{
string str1 = string.format(strtemp, reader[2].tostring(), reader[1].tostring());
sb.append("{" + str1 + "},"); //两边的大括号格式化后加上
}
reader.close();
string json = sb.tostring();
context.response.write("[" + json.substring(0, json.length - 1) + "]"); //substring的作用是去掉最后一个'逗号'
}
}
public bool isreusable {
get {
return false;
}
}
}
以上就是asp.net+jquery如何实现省市二级联动功能的方法详解的详细内容。