<asp:ScriptManager ID="ScriptManager1" runat="server" />
<cc1:AutoCompleteExtender ID="AutoCompleteExtender1" runat="server" TargetControlID="TextBox1"
ServicePath="KeyFind.asmx" CompletionSetCount="10" MinimumPrefixLength="1" ServiceMethod="GetCompleteDepart">
</cc1:AutoCompleteExtender>
<asp:TextBox ID="TextBox1" runat="server" Width="352px" Height="27px"></asp:TextBox>

using System;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
//引入空間
using System.Data;
using System.Data.OleDb;
using System.Configuration;
/// <summary>
/// KeyFind 的摘要說明
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
//添加服務腳本（必須添，否則程序不能正常運行）
[System.Web.Script.Services.ScriptService]
public class KeyFind : System.Web.Services.WebService
{
public KeyFind()
{
//如果使用設計的組件，請取消注釋以下行
//InitializeComponent();
}
//定義數組保存獲取的內容
private string[] autoCompleteWordList = null;
//兩個參數“prefixText”表示用戶輸入的前綴，count表示返回的個數
[WebMethod]
public String[] GetCompleteDepart(string prefixText, int count)
{
///檢測參數是否為空
if (string.IsNullOrEmpty(prefixText) == true || count <= 0) return null;
// 如果數組為空
if (autoCompleteWordList == null)
{
//讀取數據庫的內容
OleDbConnection conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("Ex18_02.mdb"));
conn.Open();
OleDbDataAdapter da = new OleDbDataAdapter("select keyName from keyInfo where keyName like'" + prefixText + "%' order by keyName", conn);
DataSet ds = new DataSet();
da.Fill(ds);
//讀取內容文件的數據到臨時數組
string[] temp = new string[ds.Tables[0].Rows.Count];
int i = 0;
foreach (DataRow dr in ds.Tables[0].Rows)
{
temp[i] = dr["keyName"].ToString();
i++;
}
Array.Sort(temp, new CaseInsensitiveComparer());
//將臨時數組的內容賦給返回數組
autoCompleteWordList = temp;
if (conn.State == ConnectionState.Open)
conn.Close();
}
//定位二叉樹搜索的起點
int index = Array.BinarySearch(autoCompleteWordList, prefixText, new CaseInsensitiveComparer());
if (index < 0)
{ //修正起點
index = ~index;
}
//搜索符合條件的數據
int matchCount = 0;
for (matchCount = 0; matchCount < count && matchCount + index < autoCompleteWordList.Length; matchCount++)
{ ///查看開頭字符串相同的項
if (autoCompleteWordList[index + matchCount].StartsWith(prefixText, StringComparison.CurrentCultureIgnoreCase) == false)
{
break;
}
}
//處理搜索結果
string[] matchResultList = new string[matchCount];
if (matchCount > 0)
{ //復制搜索結果
Array.Copy(autoCompleteWordList, index, matchResultList, 0, matchCount);
}
return matchResultList;
}
}