用AjaxPro实现二级联动

时间：2010-10-09 来源：The Coder.
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Test.aspx.cs" Inherits="Test" %>

<!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>AjaxPro实现二级联动</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <table width="200" border="0" align="center" cellpadding="3" cellspacing="1" bordercolor="#FFFFFF" style="border-collapse: collapse">
                                <tr align="center">
                                  <td height="20" colspan="2">
                                      <strong>AjaxPro实现二级联动</strong> </td>
                                </tr>
                                <tr class="tdbg" >
                                  <td width="30%">
                                      省份</td>
                                  <td width="70%" align="left">
                                          <asp:DropDownList ID="ddlStateList" runat="server" DataTextField="StateName" DataValueField="StateId">
                                          </asp:DropDownList></td>
                                </tr>
                                <tr class="tdbg" >
                                  <td><strong>城市</strong></td>
                                  <td align="left">
                                          <asp:DropDownList ID="ddlCityList" runat="server">
                                          </asp:DropDownList></td>
                                </tr>
                              </table>
    
    </div>
    <script language="javascript" type="text/javascript" defer="defer"> 
    function ShowCity(id)
    {
        var res=Test.GetCityList(parseInt(id)).value;
        var ddl=document.getElementById("<%=ddlCityList.UniqueID %>");
        ddl.length=0;
        if(res)
        {
            //res是服务器返回的一个List<City>集合
            for(var i=0;i<res.length;i++)
            {
                ddl.options.add(new Option(res[i].CityName,res[i].CityId));
                //从上面可以看出可以直接调用List<City>集合中的元素和它们的属性
            }
        }
    }
</script>
    </form>
</body>
</html>
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Collections.Generic;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;


/**
 * 写作说明：本文展示了如何利用AjaxPro与服务器交互，并且还展示了在Js中可以直接调用服务器返回的集合和直接调用服务器上class的属性
 * 作者：周公
 * 日期：2008-1-1
 * 首发地址：http://blog.csdn.net/zhoufoxcn/
 **/
public partial class Test : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            List<State> stateList = new List<State>(10);
            stateList.Add(new State(0, "选择城市"));//默认选项
            stateList.Add(new State(1,"北京"));
            stateList.Add(new State(2, "天津"));
            stateList.Add(new State(3, "上海"));
            stateList.Add(new State(4, "湖北"));
            stateList.Add(new State(5, "湖南"));
            stateList.Add(new State(6, "山西"));
            ddlStateList.DataSource = stateList;
            ddlStateList.DataBind();
            ddlStateList.Attributes["onchange"] = "ShowCity(this.options[selectedIndex].value)";
        }
        AjaxPro.Utility.RegisterTypeForAjax(typeof(Test));//注册
    }
    [AjaxPro.AjaxMethod]
    public List<City> GetCityList(int stateId)
    {
        //呵呵，都是我熟悉的城市或者区
        List<City> cityList = new List<City>(12);
        cityList.Add(new City(11, "海淀区", 1));
        cityList.Add(new City(12, "朝阳区", 1));
        cityList.Add(new City(13, "大港区", 2));
        cityList.Add(new City(14, "南开区", 2));
        cityList.Add(new City(15, "普陀区", 3));
        cityList.Add(new City(16, "黄浦区", 3));
        cityList.Add(new City(17, "黄冈市", 4));
        cityList.Add(new City(18, "荆州市", 4));
        cityList.Add(new City(19, "长沙市", 5));
        cityList.Add(new City(20, "岳阳市", 5));
        cityList.Add(new City(21, "太原市", 6));
        cityList.Add(new City(22, "大同市", 6));
        List<City> tempList = new List<City>();
        for (int i = 0; i < cityList.Count; i++)
        {
            if (cityList[i].StateId == stateId)
            {
                tempList.Add(cityList[i]);
            }
        }
        return tempList;
    }
}
/// <summary>
/// 省份信息
/// </summary>
public class State
{
    private int stateId;
    private string stateName;
    /// <summary>
    /// 省份名
    /// </summary>
    public string StateName
    {
        get { return stateName; }
        set { stateName = value; }
    }
    
    /// <summary>
    /// 省份编号
    /// </summary>
    public int StateId
    {
        get { return stateId; }
        set { stateId = value; }
    }
    public State(int stateId, string stateName)
    {
        this.stateId = stateId;
        this.stateName = stateName;
    }
}
/// <summary>
/// 城市信息
/// </summary>
public class City
{
    private int cityId;
    private int stateId;
    private string cityName;
    /// <summary>
    /// 城市名称
    /// </summary>
    public string CityName
    {
        get { return cityName; }
        set { cityName = value; }
    }
    
    /// <summary>
    /// 城市所在省份编号
    /// </summary>
    public int StateId
    {
        get { return stateId; }
        set { stateId = value; }
    }
    
    /// <summary>
    /// 城市编号
    /// </summary>
    public int CityId
    {
        get { return cityId; }
        set { cityId = value; }
    }

    public City(int cityId, string cityName, int stateId)
    {
        this.cityId = cityId;
        this.cityName = cityName;
        this.stateId = stateId;
    }
    
}