asp.net省市三级联动的DropDownList+Ajax的三种框架(aspnet/Jquery/ExtJs)示例

本文主要列举了省市三级联动的DropDownList+Ajax的三种框架(aspnet/Jquery/ExtJs)示例。前段时间需要作一个的Web前端应用，需要用多个框架，一个典型的应用场景是省市三级联动，基于此应用，特将三种主要的ajax框架略作整理，方便有需要的朋友查阅。

在示例之前，我们先设置一个演示数据源，新建一个项目，项目结构如图：

主要文件如下：
AreaModel.cs:


代码如下:

using System;
using System.Collections.Generic;
namespace Downmoon.Framework.Model
{
#region PopularArea
public class Area
{
private string m_Area_ID;
/// <summary>
/// 地区编号
/// </summary>
public string Area_ID
{
get { return m_Area_ID; }
set { m_Area_ID = value; }
}
private string m_Area_Name;
/// <summary>
/// 地区名称
/// </summary>
public string Area_Name
{
get { return m_Area_Name; }
set { m_Area_Name = value; }
}
private double m_Area_Order;
/// <summary>
/// 排序
/// </summary>
public double Area_Order
{
get { return m_Area_Order; }
set { m_Area_Order = value; }
}
private int m_Area_Layer;
/// <summary>
/// 层级
/// </summary>
public int Area_Layer
{
get { return m_Area_Layer; }
set { m_Area_Layer = value; }
}
private string m_Area_FatherID;
/// <summary>
/// 父级ID
/// </summary>
public string Area_FatherID
{
get { return m_Area_FatherID; }
set { m_Area_FatherID = value; }
}
public Area() { }
public Area(string id, string name, double order, int layer, string father)
{
this.Area_ID = id;
this.Area_Name = name;
this.m_Area_Order = order;
this.m_Area_Layer = layer;
this.m_Area_FatherID = father;
}
}
#endregion
}

AreaControl.cs:


代码如下:

using System;
using System.Collections.Generic;
using Downmoon.Framework.Model;
namespace Downmoon.Framework.Controllers
{
public class AreaList : IArea
{
// Area singleton
private static AreaList instance;
public static AreaList Instance
{
get
{
if (AreaList.instance == null)
{
AreaList.instance = new AreaList();
}
return AreaList.instance;
}
}
public List<Area> GetAreaList()
{
List<Area> Areas = new List<Area>();
Areas.Add(new Area("110000", "北京市", 0, 1, "000000"));
Areas.Add(new Area("110100", "市辖区", 0, 2, "110000"));
Areas.Add(new Area("110101", "东城区", 0, 3, "110100"));
Areas.Add(new Area("110102", "西城区", 0, 3, "110100"));
Areas.Add(new Area("110103", "崇文区", 0, 3, "110100"));
Areas.Add(new Area("330000", "浙江省", 0, 1, "000000"));
Areas.Add(new Area("330100", "杭州市", 0, 2, "330000"));
Areas.Add(new Area("330200", "宁波市", 0, 2, "330000"));
Areas.Add(new Area("330102", "上城区", 0, 3, "330100"));
Areas.Add(new Area("330103", "下城区", 0, 3, "330100"));
Areas.Add(new Area("330104", "江干区", 0, 3, "330100"));
Areas.Add(new Area("330105", "拱墅区", 0, 3, "330100"));
Areas.Add(new Area("330106", "西湖区", 0, 3, "330100"));
Areas.Add(new Area("330203", "海曙区", 0, 3, "330200"));
Areas.Add(new Area("330204", "江东区", 0, 3, "330200"));
Areas.Add(new Area("330205", "江北区", 0, 3, "330200"));
Areas.Add(new Area("330206", "北仑区", 0, 3, "330200"));
Areas.Add(new Area("330211", "镇海区", 0, 3, "330200"));
return Areas;
}
public List<Area> GetAreaListFindByParentID(string filter)
{
return GetAreaList().FindAll(
delegate(Area ar)
{
return ar.Area_FatherID == filter;
}
);
}
}
}

Factory.cs


代码如下:

using System;
using System.Collections.Generic;
//using Downmoon.Framework.Model;
namespace Downmoon.Framework.Controllers
{
public class Factory
{
public static IArea GetAreaController()
{
return AreaList.Instance;
}
}
}

IArea.cs


代码如下:

using System;
using System.Collections.Generic;
using System.Text;
using Downmoon.Framework.Model;
namespace Downmoon.Framework.Controllers
{
public interface IArea
{
List<Area> GetAreaList();
List<Area> GetAreaListFindByParentID(string filterID);
}
}

一、基于aspnet自带的Ajax框架，主要好处是与asp.net完全集成，无需写过多的 js。缺点是在framework2下需作一些设置，在Framework 4下无需设置。
Framework 2：

需首先在web.config文件中作配置：

代码如下:

<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
<sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere" />
<section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
</sectionGroup>
</sectionGroup>
</sectionGroup>
</configSections>
<system.web>
<customErrors defaultRedirect="" />
<trace mostRecent="true" pageOutput="true" />
<pages>
<controls>
<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</controls>
</pages>
<compilation>
<assemblies>
<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</assemblies>
</compilation>
<httpHandlers>
<remove verb="*" path="*.asmx"/>
<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
</httpHandlers>
<httpModules>
<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</httpModules>
</system.web>

<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<modules>
<add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</modules>
<handlers>
<remove name="WebServiceHandlerFactory-Integrated" />
<add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode"
type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode"
type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</handlers>
</system.webServer>
</configuration>

前台页面：


代码如下:

<asp:ScriptManager ID="ScriptManager1" runat="server" EnablePartialRendering="true">
</asp:ScriptManager>
<div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
<table width="500" border="0" cellpadding="0" cellspacing="2" >
<tr>
<td height="25" bgcolor="#EAEAEA" >
请选择省/市/区：
</td>
<td bgcolor="#f7f7f7">
<asp:DropDownList ID="dpProvince" runat="server"
AutoPostBack="true" onselectedindexchanged="dpProvince_SelectedIndexChanged" />
<asp:DropDownList ID="dpCity" runat="server" AutoPostBack="true"
onselectedindexchanged="dpCity_SelectedIndexChanged" />
<asp:DropDownList ID="dpArea" runat="server" AutoPostBack="false"
/>
</td>
</tr>
<tr>
<td height="25" bgcolor="#EAEAEA" >
</td>
<td bgcolor="#f7f7f7">
<asp:UpdateProgress ID="UpdateProgress1" runat="server">
<ProgressTemplate>
正在查询，请稍候……………………</ProgressTemplate>
</asp:UpdateProgress>
</td>
</tr>

</table>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="dpProvince" EventName="SelectedIndexChanged" />
<asp:AsyncPostBackTrigger ControlID="dpCity" EventName="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
</div>

Framework 4：与代码完全一样，只是无需在web.config中作配置。

如图：

二、基于JQuery1.4.1的Ajax框架，主要好处是与后续版本的asp.net完全集成。

基于ashx作一个 Request，主要代码：

代码如下:

using System;
using System.Collections.Generic;
using System.Web;
using Downmoon.Framework.Controllers;
using Downmoon.Framework.Model;
using System.Text;
namespace dropdown_JQuery14_Net2
{
/// <summary>
/// Summary description for AjaxRequest
/// </summary>
public class AjaxRequest : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
string Area_FatherID = string.Empty;
if (context.Request["pid"] != null)
{ Area_FatherID = context.Request["pid"].ToString(); }
string parentId = string.Empty;
//mydbDataContext db = new mydbDataContext();
//根据传过来的Value值 进行查询
//List<ChinaStates> list = db.ChinaStates.Where(c => c.ParentAreaCode == strId).ToList();
List<Area> list = Factory.GetAreaController().GetAreaListFindByParentID(Area_FatherID);
context.Response.ContentType = "application/json";
context.Response.ContentEncoding = Encoding.UTF8;
context.Response.Write(ListToJson(list));
context.Response.End();
}
public string ListToJson(List<Area> list)
{
StringBuilder sb = new StringBuilder();
if (list != null)
{
sb.Append("[");
for (int i = 0; i < list.Count; i++)
{
sb.Append("{");
sb.Append("\"Area_ID\":\"" + list[i].Area_ID + "\",");
sb.Append("\"Area_Name\":\"" + list[i].Area_Name + "\"");
//sb.Append("\"Area_FatherID\":\"" + list[i].Area_FatherID + "\"");
if (i != list.Count - 1)
{
sb.Append("},");
}
}
}
sb.Append("}");
sb.Append("]");
return sb.ToString();
}
public bool IsReusable
{
get
{
return false;
}
}
}
}

前台：aspx


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 runat="server">
<title></title>
<mce:style type="text/css"><!--
#dpCity
{
display: none;
position: relative;
}
#dpArea
{
display: none;
position: relative;
}

--></mce:style><style type="text/css" mce_bogus="1"> #dpCity
{
display: none;
position: relative;
}
#dpArea
{
display: none;
position: relative;
}
</style>
<mce:script language="javascript" type="text/javascript" src="Scripts/jquery-1.4.1.js" mce_src="Scripts/jquery-1.4.1.js"></mce:script>
</head>
<body>
<form id="form1" runat="server">
<div>
请选择省/市/区： <asp:DropDownList ID="dpProvince" runat="server" />
<asp:DropDownList ID="dpCity" runat="server">
</asp:DropDownList>
<asp:DropDownList ID="dpArea" runat="server" AutoPostBack="false" />
</div>
<mce:script language="javascript" type="text/javascript"><!--

$(function () {
var $dp1 = $("#dpProvince");
var $dp2 = $("#dpCity");
var $dp3 = $("select[name$=dpArea]");
$dp1.focus();
//alert($dpCity);
loadAreas("000000", "0");
$dp1.bind("change keyup", function () {
if ($(this).val() != "") {
//alert($("select option:selected").val());
//loadAreas($("select option:selected").val(), "1");
var strPid = $dp1.attr("value"); //获取城市
loadAreas(strPid, "1");
$dp2.fadeIn("slow");
} else {
$dp2.fadeOut("slow");
}
});
$dp2.bind("change keyup", function () {
var strCId = $dp2.attr("value"); //获取城市
if ($(this).val() != "") {
loadAreas(strCId, "2");
$dp3.fadeIn("slow");
} else {
$dp3.fadeOut("slow");
}
});
});
function loadAreas(selectedItem, level) {
$.getJSON("AjaxRequest.ashx?pid=" + selectedItem, function (data) {
switch (level) {
case "0":
$("#dpProvince").html("");
$("#dpProvince").append("<option value='' selected='selected'>请选择...</option>");
for (var i = 0; i < data.length; i++) {
$("#dpProvince").append($("<option></option>").val(data[i].Area_ID).html(data[i].Area_Name));
};
break;
case "1":
$("#dpCity").html("");
$("#dpCity").append("<option value='' selected='selected'>请选择...</option>");
for (var i = 0; i < data.length; i++) {
$("#dpCity").append($("<option></option>").val(data[i].Area_ID).html(data[i].Area_Name));
};
break;
case "2":
$("#dpArea").html("");
$("#dpArea").append("<option value='' selected='selected'>请选择...</option>");
for (var i = 0; i < data.length; i++) {
$("#dpArea").append($("<option></option>").val(data[i].Area_ID).html(data[i].Area_Name));
};
break;

default:
break;
}
});
}

// --></mce:script>
</form>
</body>
</html>

三、基于ExtJS 3.2的Ajax框架。
后台ashx:


代码如下:

using System;
using System.Collections.Generic;
using System.Web;
using Downmoon.Framework.Controllers;
using Downmoon.Framework.Model;
using System.Text;
namespace dropdown_ExtJS32_Net2.Ajax
{
/// <summary>
/// Summary description for GetAreaXml
/// </summary>
public class GetAreaXml : IHttpHandler
{
//string baseCode = "000000";
public void ProcessRequest(HttpContext context)
{
string parentId = "000000";
if (context.Request["pid"] != null)
{
parentId = context.Request["pid"].ToString();
}
//parentId = (parentId.Length > 0) ? parentId : "000000";
////string parentId2 = "000000";
////if (context.Request["pid2"] != null)
////{
//// parentId2 = context.Request["pid2"].ToString();
////}
#region tony 2010.2.7 update
List<Area> list = new List<Area>();
//if (parentId.Length > 0)
//{
list = Factory.GetAreaController().GetAreaListFindByParentID(parentId);
//}
////else if (parentId2.Length > 0)
////{
//// list = Factory.GetAreaController().GetAreaListFindByParentID(parentId2);
////}
#endregion
context.Response.AddHeader("Cache-Control", "no-cache, must-revalidate");
context.Response.ContentEncoding = System.Text.Encoding.UTF8;
context.Response.ContentType = "text/html";
StringBuilder sb = new StringBuilder();

for (int i = 0; i < list.Count; i++)
{
sb.Append("{\"Area_Name\":\"" + list[i].Area_Name + "\",");
sb.Append("\"Area_ID\":\"" + list[i].Area_ID + "\"},");
}
string json = sb.ToString().TrimEnd(',');
context.Response.Write("{\"Results\":[" + json + "]}");

}
public bool IsReusable
{
get
{
return false;
}
}
}
}

前台页面.aspx


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 runat="server">
<title>demo a dropdownlist by extjs 3.2 </title>
<link rel="stylesheet" href="Scripts/ext/3.2/resources/css/ext-all.css" mce_href="Scripts/ext/3.2/resources/css/ext-all.css" />
<mce:script type="text/javascript" src="Scripts/ext/3.2/adapter/ext/ext-base.js" mce_src="Scripts/ext/3.2/adapter/ext/ext-base.js"></mce:script>
<mce:script type="text/javascript" src="Scripts/ext/3.2/ext-all.js" mce_src="Scripts/ext/3.2/ext-all.js"></mce:script>
<mce:script type="text/javascript"><!--
Ext.onReady(function () {
//alert("extjs is Ok!");
});
function $() {
return Ext.get(arguments[0]);
}
/*Area*/
function GetAreas() {
//alert($(arguments[1]));
var cityCtrl = $(arguments[1]).child("select");
var cityCtrlContainer = $(arguments[1]);
cityCtrl.dom.options.length = 0;
if ($(arguments[0]).getValue() == "") { cityCtrlContainer.hide(); return; }

cityCtrl.disabled = true;
var selectValue2 = $(arguments[0]).getValue();
Ext.Ajax.request({
url: arguments[2],
params: { pid: selectValue2 },
method: 'GET',
success: function (result, request) {
//alert(params);
var jsonData = Ext.util.JSON.decode(result.responseText);
//alert(jsonData.Results.length);
if (jsonData.Results.length > 0) {
cityCtrl.dom.options.add(new Option("请选择", "000000"));
for (var i = 0; i < jsonData.Results.length; i++) {
cityCtrl.dom.options.add(new Option(jsonData.Results[i].Area_Name, jsonData.Results[i].Area_ID));
}
cityCtrl.disabled = false;
cityCtrlContainer.show();
}
else {
cityCtrlContainer.hide();
}
},
failure: function (result, request) { Ext.MessageBox.alert('Failed', 'Successfully posted form: ' + action.date); }
});
}

// --></mce:script>
</head>
<body>
<form id="form1" runat="server">
<table width="500" border="0" cellpadding="0" cellspacing="2">
<tr>
<td height="25" bgcolor="#EAEAEA">
<div style="float: left; height: 20px; line-height: 20px;">
请选择</div>
<asp:DropDownList Style="float: left;" mce_Style="float: left;" ID="dropProvince" runat="server" />
<div style="float: left; height: 20px; line-height: 20px;">
省</div>
<asp:Panel ID="panelArea" runat="server">
<asp:DropDownList Style="float: left;" mce_Style="float: left;" ID="dropArea" runat="server" />
<div style="float: left; height: 20px; line-height: 20px;">
市</div>
</asp:Panel>
<asp:Panel ID="panelArea2" runat="server" >
<asp:DropDownList Style="float: left;" mce_Style="float: left;" ID="dropArea2" runat="server" />
<div style="float: left; height: 20px; line-height: 20px;">
县</div>
</asp:Panel>
</td>
</tr>
</table>
</form>
</body>
</html>

效果如图：


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