Ajax实现联动下拉菜单的问题

js有错误，或浏览器问题，用js写的时候，js一旦多的时候总是会出现js错误，刷新浏览器尝试，只要成功一次，说明你程序没有什么大问题！

后来发现在出现上述情况后，点击刷新网页，刷新非常缓慢，且无法通过其他连接跳转到别的为网页，现象为点击任何连接没有任何响应，谁能帮助一下。
我的平台VS2003,SQL2000,使用了AJAX

http://blog.csdn.net/lifuyun/archive/2007/09/21/1794085.aspx
参考资料，望对你有帮助或启示！

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Car.aspx.cs" Inherits="Car" %><!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>车型、车系性能测试</title>    <script language="javascript" type="text/javascript">
    function changeBrand()
    {
        var context="";
        var arg="Type,"+document.getElementById('brand').value;
        <%= Page.ClientScript.GetCallbackEventReference(this, "arg", "bindType", "context") %>
    }
    function bindType(response)
    {
        eval("List="+response);
        var typeList=document.getElementById('type');
        typeList.options.length   =   0;   //clear   all
        typeList.options[typeList.options.length]   =   new   Option("请选择",   "0",   true,   true);

         var seriesList=document.getElementById('series');
        seriesList.options.length   =   0;   //clear   all
        seriesList.options[seriesList.options.length]   =   new   Option("请选择",   "0",   true,   true);


        for(var i=0;i<List.length;i++)
        {
            var element=document.createElement("option");
            element.innerText=List[i].Name;
            element.value=List[i].Id;
            typeList.appendChild(element);
        }
    }

    function changeType()
    {
        var context="";
        var arg="Series,"+document.getElementById('type').value+","+document.getElementById('brand').value;
        <%= Page.ClientScript.GetCallbackEventReference(this, "arg", "BindSeries", "context") %>
    }

    function BindSeries(response)
    {
//        alert(response);
        eval("List="+response);
        var seriesList=document.getElementById('series');
        seriesList.options.length   =   0;   //clear   all
        seriesList.options[seriesList.options.length]   =   new   Option("请选择",   "0",   true,   true);
        for(var i=0;i<List.length;i++)
        {
            var element=document.createElement("option");
            element.innerText=List[i].Name;
            element.value=List[i].Id;
            seriesList.appendChild(element);
        }
    }

    function initDropDownList(response)
    {
//        alert(response);
        eval("List="+response);
        var brandList=document.getElementById('brand');
        brandList.options[brandList.options.length] =   new   Option("请选择",   "0",   true,   true);
        for(var i=0;i<List.length;i++)
        {
            var element=document.createElement("option");
            if(List[i].Name)
            element.innerText=List[i].Name;
            element.value=List[i].Id;
            brandList.appendChild(element);
        }
    }
    function InitPage()
    {
        var arg="init";
        var context="";
        <%= Page.ClientScript.GetCallbackEventReference(this, "arg", "initDropDownList", "context") %>
    }
    </script></head>
<body onload="InitPage()">
    <form id="form1" runat="server">
        <div>
            <select id="brand" name="brand" onchange="changeBrand()">
            </select>
            <select id="type" name="type" onchange="changeType()">
            </select>
            <select id="series" name="series">
            </select>
            <asp:Button ID="btnClear" runat="server" OnClick="btnClear_Click" Text="清空数据" />
            <asp:Button ID="btnCache" runat="server" OnClick="btnCache_Click" Text="生成数据" />
        </div>
    </form>
</body>
</html>

using System;
using System.Data;
using System.Configuration;
using System.Collections;
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;public partial class Car : System.Web.UI.Page, ICallbackEventHandler
{
    DataTable dtFactory = new DataTable("Factory");
    DataColumn dcFactoryId = new DataColumn("ID", Type.GetType("System.Int32"));
    DataColumn dcFactoryName = new DataColumn("Name", Type.GetType("System.String"));    DataTable dtType = new DataTable("Type");
    DataColumn dcTypeId = new DataColumn("ID", Type.GetType("System.Int32"));
    DataColumn dcTypePId = new DataColumn("PID", Type.GetType("System.Int32"));
    DataColumn dcTypeName = new DataColumn("Name", Type.GetType("System.String"));    DataTable dtSeries = new DataTable("Series");
    DataColumn dcSeriesId = new DataColumn("ID", Type.GetType("System.Int32"));
    DataColumn dcSeriesPId = new DataColumn("PID", Type.GetType("System.Int32"));
    DataColumn dcSeriesFId = new DataColumn("FID", Type.GetType("System.Int32"));
    DataColumn dcSeriesName = new DataColumn("Name", Type.GetType("System.String"));    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
        }
    }    private void FillData()
    {
        for (int i = 0; i < 100; i++)
        {
            DataRow drFactory = dtFactory.NewRow();
            //drFactory["dcFactoryId"] = i;
            drFactory["Name"] = string.Format("品牌{0}", i);
            dtFactory.Rows.Add(drFactory);
            for (int j = 0; j < 20; j++)
            {
                DataRow drType = dtType.NewRow();
                drType["ID"] = j;
                drType["PID"] = i;
                drType["Name"] = string.Format("品牌{0}车型{1}", i - 1, j);
                dtType.Rows.Add(drType);
                for (int k = 0; k < 20; k++)
                {
                    DataRow drSeries = dtSeries.NewRow();
                    drSeries["FID"] = i;
                    drSeries["PID"] = j;
                    drSeries["Name"] = string.Format("品牌{0}车型{1}车系{2}", i - 1, j, k);
                    dtSeries.Rows.Add(drSeries);
                }
            }
        }
        if (Cache["Factory"] == null)
        {
            Cache.Insert("Factory", dtFactory, null, DateTime.MaxValue, TimeSpan.Zero);
        }
        if (Cache["Type"] == null)
        {
            Cache.Insert("Type", dtType, null, DateTime.MaxValue, TimeSpan.Zero);
        }
        if (Cache["Series"] == null)
        {
            Cache.Insert("Series", dtSeries, null, DateTime.MaxValue, TimeSpan.Zero);
        }
    }    private void BuiltTable()
    {
        dcFactoryId.AutoIncrement = true;
        dcFactoryId.AutoIncrementSeed = 1;
        dcFactoryId.AutoIncrementStep = 1;        dtFactory.Columns.Add(dcFactoryId);
        dtFactory.Columns.Add(dcFactoryName);        dtType.Columns.Add(dcTypeId);
        dtType.Columns.Add(dcTypePId);
        dtType.Columns.Add(dcTypeName);        dcSeriesId.AutoIncrement = true;
        dcSeriesId.AutoIncrementSeed = 1;
        dcSeriesId.AutoIncrementStep = 1;        dtSeries.Columns.Add(dcSeriesId);
        dtSeries.Columns.Add(dcSeriesPId);
        dtSeries.Columns.Add(dcSeriesFId);
        dtSeries.Columns.Add(dcSeriesName);
    }    #region ICallbackEventHandler 成员    private string eventArgument = string.Empty;    public string GetCallbackResult()
    {
        System.Web.Script.Serialization.JavaScriptSerializer Serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
        string returnValue = string.Empty;
        switch (eventArgument)
        {
            case "init":
                DataTable dt = (DataTable)Cache["Factory"];
                Factory[] factories = new Factory[dt.Rows.Count];
                if (dt.Rows.Count > 0)
                {
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        factories[i] = new Factory(Convert.ToInt32(dt.Rows[i]["ID"]), dt.Rows[i]["Name"].ToString());
                    }
                }
                returnValue = Serializer.Serialize(factories);
                break;
            default:
                string[] args = eventArgument.Split(',');
                if (args[0] == "Type")
                {
                    DataRow[] drs = ((DataTable)Cache["Type"]).Select("PID=" + args[1]);
                    CarType[] types = new CarType[drs.Length];
                    if (drs.Length > 0)
                    {
                        for (int i = 0; i < drs.Length; i++)
                        {
                            types[i] = new CarType(Convert.ToInt32(drs[i]["ID"]), Convert.ToInt32(drs[i]["PID"]), drs[i]["Name"].ToString());
                        }
                    }
                    returnValue = Serializer.Serialize(types);
                    break;                }
                else if (args[0] == "Series")
                {
                    DataRow[] drs = ((DataTable)Cache["Series"]).Select("PID=" + args[1] + "AND FID=" + args[2]);
                    Series[] series = new Series[drs.Length];
                    if (drs.Length > 0)
                    {
                        for (int i = 0; i < drs.Length; i++)
                        {
                            series[i] = new Series(Convert.ToInt32(drs[i]["ID"]), Convert.ToInt32(drs[i]["PID"]), Convert.ToInt32(drs[i]["FID"]), drs[i]["Name"].ToString());
                        }
                    }
                    returnValue = Serializer.Serialize(series);
                    break;
                }
                break;
        }
        return returnValue;
    }    public void RaiseCallbackEvent(string eventArgument)
    {
        this.eventArgument = eventArgument;
    }    #endregion    public class Factory
    {
        public Factory(int id, string name)
        {
            this.id = id;
            this.name = name;
        }        int id;        public int Id
        {
            get { return id; }
            set { id = value; }
        }
        string name;        public string Name
        {
            get { return name; }
            set { name = value; }
        }
    }    public class CarType
    {
        public CarType(int id, int pid, string name)
        {
            this.id = id;
            this.pid = pid;
            this.name = name;
        }        int id;        public int Id
        {
            get { return id; }
            set { id = value; }
        }
        int pid;        public int Pid
        {
            get { return pid; }
            set { pid = value; }
        }
        string name;        public string Name
        {
            get { return name; }
            set { name = value; }
        }
    }    public class Series
    {
        public Series(int id, int pid, int fid, string name)
        {
            this.id = id;
            this.pid = pid;
            this.fid = fid;
            this.name = name;
        }        int id;        public int Id
        {
            get { return id; }
            set { id = value; }
        }
        int fid;        public int Fid
        {
            get { return fid; }
            set { fid = value; }
        }
        int pid;        public int Pid
        {
            get { return pid; }
            set { pid = value; }
        }
        string name;        public string Name
        {
            get { return name; }
            set { name = value; }
        }
    }
}

    protected void btnClear_Click(object sender, EventArgs e)
    {
        if (Cache["Factory"] == null)
        {
            Page.ClientScript.RegisterStartupScript(this.GetType(), "key", "<script language=javascript>alert('数据已经清空，请勿重复操作')</script>");
            return;
        }
        Cache.Remove("Factory");
        Cache.Remove("Type");
        Cache.Remove("Series");
    }
protected void btnCache_Click(object sender, EventArgs e)
    {
        if (Cache["Factory"] != null)
        {
            Page.ClientScript.RegisterStartupScript(this.GetType(), "key", "<script language=javascript>alert('数据已经生成，请勿重复操作')</script>");
            return;
        }
        BuiltTable();
        FillData();
    }

哇
那么多代码呀
用ajax或xmlHtml呀

调试易

Ajax实现联动下拉菜单的问题

解决方案 »