搜索功能 自动完成输入提示

搜索功能
自动完成输入提示：
VS2010工具栏添加新项AjaxControlToolkit.dll

前台：
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
        搜索 ：
        <asp:TextBox ID="txtSearch" runat="server" Height="25px" Width="359px"></asp:TextBox>
        <asp:AutoCompleteExtender
        ID="AutoCompleteExtender1"
        runat="server"
        TargetControlID="txtSearch"
        ServicePath="AutoComplete.asmx"
        ServiceMethod="GetCompletionList"
        MinimumPrefixLength="2"
        CompletionSetCount="10"
        ></asp:AutoCompleteExtender>

        <!--MinimumPrefixLength:出现提示时的文字最小长度，CompletionSetCount：文本提示的个数-->

WebServices 服务：
==================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;

/// <summary>
///AutoComplete 的摘要说明
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
//若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。
[System.Web.Script.Services.ScriptService]
public class AutoComplete : System.Web.Services.WebService {

    public AutoComplete () {

        //如果使用设计的组件，请取消注释以下行
        //InitializeComponent();
    }

    [WebMethod]
    public string HelloWorld() {
        return "Hello World";
    }

    [WebMethod]
    public string[] GetCompletionList(string prefixText, int count)
    {
        List<string> strList = new List<string>();
        count = count == 0 ? 10 : count;
        Random r = new Random();
       
        for (int i = 0; i < count; i++)
        {
          string newStr= ((char)(r.Next(65, 90))+(char)(r.Next(97, 122))+(char)(r.Next(97,122))).ToString();
          strList.Add(prefixText + newStr);
        }
        return strList.ToArray();
    }

}