ajax autocomplete extender is not working - asp.net

Question

I have an autocompleate extender on textbox which shows records as a list from database but whern I click on texbox and start typing nothing happned. my html code is
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:AutoCompleteExtender ID="TextBox1_AutoCompleteExtender" runat="server"
Enabled="True" TargetControlID="TextBox1" ServicePath="~/WebService.asmx"
ServiceMethod="GetCompletionList"
MinimumPrefixLength="2"
CompletionInterval="1000"
EnableCaching="true"
CompletionSetCount="20"
DelimiterCharacters=";, :"
ShowOnlyCurrentWordInCompletionListItem="true" >
</asp:AutoCompleteExtender>
And my web service is
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data;
using MySql.Data.MySqlClient;
using System.Configuration;
/// <summary>
/// Summary description for WebService
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
// [System.Web.Script.Services.ScriptService]
public class WebService : System.Web.Services.WebService {
public WebService () {
//Uncomment the following line if using designed components
//InitializeComponent();
}
[WebMethod]
public static List<string> GetCompletionList(string prefixText, int count)
{
MySqlConnection con = new MySqlConnection(ConfigurationManager.AppSettings["cn"]);
if (con.State == ConnectionState.Closed)
con.Open();
MySqlCommand cmd = new MySqlCommand("SELECT gotra FROM tbgotra WHERE gotra LIKE '%" + prefixText + "%'",con);
List<string> k = new List<string>();
using (MySqlDataReader sdr = cmd.ExecuteReader())
{
while (sdr.Read())
{
k.Add(sdr["gotra"].ToString());
}
}
con.Close();
return k;
}
}

Answer 1

Try adding this line, i remember i had the same problem once where it worked for me locally but not live.
[WebMethod]
[System.Web.Script.Services.ScriptMethod] <-- Add this line
public static List<string> GetCompletionList(string prefixText, int count)
....

Answer 2

you Should to use
<asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"></asp:ToolkitScriptManager>
in before the TextBox1

Answer 3

try this signature for web method:
public string[] GetCompletionList(string prefixText, int count, string contextKey)
I think extender wont accept any other return type besides string[]

Answer 4

In my case, I had to un-comment this line in the ASMX file
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
// [System.Web.Script.Services.ScriptService]

Answer 5

In my case it was issue with the css class below, I've had it in the source but without z-index property.
<ajaxToolkit:AutoCompleteExtender ID="AutoCompleteExtender2" runat="server"
ClientIDMode="Static" MinimumPrefixLength="1" ServiceMethod="GetAllStaff"
TargetControlID="txtTeacherName" ServicePath="~/webservices/WebService.asmx"
CompletionInterval="50" EnableCaching="true" CompletionSetCount="20"
ShowOnlyCurrentWordInCompletionListItem="true"
CompletionListCssClass="CompletionListCssClass">
</ajaxToolkit:AutoCompleteExtender>
<style>
.CompletionListCssClass {
font-size: 12px;
color: #000;
padding: 3px 5px;
border: 1px solid #999;
background: #fff;
width: 300px;
float: left;
position: absolute;
margin-left: 0;
overflow: auto;
height: 200px;
cursor: pointer;
z-index: 10000001 !important;
}
</style>