Generally we use AJAX AutoCompleteExtender for a TextBox to show data from database through Webservice. Here I faced a problem that to set contextKey value dyanamically from '.CS' file without fix it in AutoCompleteExtender's property that is ContextKey="value" in design view.
Nb : before using this we should have appropriate AjaxControlToolkit.dll for our .Net version.
Design Code:-
<body>
<form id="form2" runat="server">
<asp:ToolkitScriptManager
runat="server">
<Services>
<asp:ServiceReference Path="~/WebService/WebService.asmx"
/>
</Services>
</asp:ToolkitScriptManager>
<div>
<fieldset style="height: 200px; width: 365px;">
<table class="style1">
<tr>
<td
style="text-align: right">
<asp:Label ID="Label18" runat="server" Text="Designation"></asp:Label>
</td>
<td>
<asp:DropDownList ID="DropDownList1" runat="server" Height="22px" Width="142px" AutoPostBack="True"
OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged">
<asp:ListItem>Select</asp:ListItem>
<asp:ListItem>Software Engineer</asp:ListItem>
<asp:ListItem>Designer</asp:ListItem>
</asp:DropDownList>
</td>
</tr>
<tr>
<td
style="text-align: right">
<asp:Label ID="Label19" runat="server" Text="Employee"></asp:Label>
</td>
<td
style="text-align: left">
<asp:TextBox ID="TxtEmployee" runat="server" autocomplete="off"></asp:TextBox>
<asp:AutoCompleteExtender ID="TxtEmployee_AutoCompleteExtender" runat="server"
DelimiterCharacters=""
Enabled="True"
ServicePath="~/WebService/WebService.asmx"
ServiceMethod="GetEmployee"
CompletionInterval="100"
MinimumPrefixLength="0"
TargetControlID="TxtEmployee"
UseContextKey="true">
</asp:AutoCompleteExtender>
</td>
</tr>
</table>
</fieldset>
</div>
</form>
</body>
C# Code:-
private void
SetContextKey()
{
AjaxControlToolkit.AutoCompleteExtender
modal = (AjaxControlToolkit.AutoCompleteExtender)TxtEmployee.FindControl("TxtEmployee_AutoCompleteExtender");
modal.ContextKey = DropDownList1.SelectedItem.ToString();// Any constant value
}
protected void
DropDownList1_SelectedIndexChanged(object
sender, EventArgs e)
{
SetContextKey();
}
WebService Code :-
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data;
using System.Data.SqlClient;
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] // This line should
Uncomment
public class WebService : System.Web.Services.WebService {
public WebService () {
//Uncomment the following line if using designed components
//InitializeComponent();
}
[WebMethod]
public string
HelloWorld() {
return "Hello World";
}
[WebMethod]
public string[]
GetEmployee(string prefixText,int count,string
contextKey)
{
string sql = "Select
* from emp_demo Where EmpName like '"+ prefixText +"%' and Designation='"+ contextKey +"' ";
SqlDataAdapter da = new
SqlDataAdapter(sql, ConfigurationManager.ConnectionStrings["DBConnection"].ConnectionString);
DataTable dt = new
DataTable();
da.Fill(dt);
string[] country= new
string[dt.Rows.Count];
int i = 0;
foreach (DataRow
dr in dt.Rows)
{
country.SetValue(dr["EmpName"].ToString(),
i);
i++;
}
return country;
}
}
