1、打开VS，添加TextFile1.txt、WebForm1.aspx、WebService1.asmx；
2、在TextFile1.txt添加如下图所示数据：
3、在WebService1.asmx中添加GetCompleteList方法，代码如下：
GetCompleteList方法
[WebMethod] public String[] GetCompleteList(string prefixText, int count) { if (autoCompleteWordList == null) { string[] temp = File.ReadAllLines(Server.MapPath("./TextFile1.txt")); Array.Sort(temp, new CaseInsensitiveComparer()); autoCompleteWordList = temp; int index = Array.BinarySearch(autoCompleteWordList, prefixText, new CaseInsensitiveComparer()); if (index < 0) { index = ~index; } int matchingCount; for (matchingCount = 0; matchingCount < count && index + matchingCount < autoCompleteWordList.Length; matchingCount++) { if (!autoCompleteWordList[index + matchingCount].StartsWith(prefixText, StringComparison.CurrentCultureIgnoreCase)) { break; } } String[] returnValue = new string[matchingCount]; if (matchingCount > 0) { Array.Copy(autoCompleteWordList, index, returnValue, 0, matchingCount); } return returnValue; } else { autoCompleteWordList = null; return null; } }
4、在WebForm1.aspx窗体中添加源码：
WebForm1.aspx源码
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<p class="style1">省份智能提示：</p>
<asp:TextBox ID="TextBox1" runat="server" Height="18px" Width="184px"></asp:TextBox>
<br />
<asp:AutoCompleteExtender ID="AutoCompleteExtender1" runat="server" ServiceMethod="GetCompleteList"
ServicePath="~/WebService1.asmx" Enabled="true" MinimumPrefixLength="1" CompletionSetCount="8" TargetControlID="TextBox1">
</asp:AutoCompleteExtender>
</div>
</form>
</body>
5、在浏览器中查看如图：
