1與0的世界

前端：   

 <script type="text/javascript">
        function ReceiveServerData(rValue)
        {
            document.getElementById("ResultsSpan").innerHTML = rValue;
        }
    </script>

後端： 

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Collections.Specialized;

public partial class Default2 : System.Web.UI.Page,ICallbackEventHandler
{
    protected ListDictionary catalog;
    protected string returnValue;
    protected void Page_Load(object sender, EventArgs e)
    {
        string cbReference = Page.ClientScript.GetCallbackEventReference(this, "document.getElementById('" + ListBox1.ClientID + "').options[document.getElementById('" + ListBox1.ClientID + "').selectedIndex].text", "ReceiveServerData", "");

        ListBox1.Attributes.Add("onchange", cbReference);

        catalog = new ListDictionary();
        catalog.Add("螢幕", 42);
        catalog.Add("筆記型電腦", 10);
        catalog.Add("鍵盤", 23);
        catalog.Add("滑鼠", 17);
        catalog.Add("桌上型電腦", 37);
        catalog.Add("硬碟", 76);
        catalog.Add("燒錄機", 34);
        catalog.Add("電源供應器", 21);

        ListBox1.DataSource = catalog;
        ListBox1.DataTextField = "key";
        ListBox1.DataBind();
    }

    string ICallbackEventHandler.GetCallbackResult()
    {
        return returnValue;
    }
    void ICallbackEventHandler.RaiseCallbackEvent(string eventArgument)
    {
        if (catalog[eventArgument] == null)
        {
            returnValue = "-1";
        }
        else
        {
            returnValue = catalog[eventArgument].ToString();
        }
    }

}