by Santhakumar Munuswamy
Posted on 30 November 2014
ASP.NET
Dropdownlist Control:
It is enables users to select from a single-selection drop-down list. The drop-down list contain "n" number of items. The DropDownList control also supports data binding, such as data to bind the control to a data source like object data source, xml data source and sql data source, that contains the items to display in the control. This DropDownList control can be used to add data manually or even dynamically data binding from database.
DataBind Method
It is method to bind the data source to the DropDownList control
DataTextField, DataValueField Property
To specify which field in the data source to bind to the Text and Value properties of each list item in the control.
SelectedIndex Property
The SelectedIndex property to programmatically determine the index of the item selected by the user from the DropDownList control
Dropdownlist.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Dropdownlist.aspx.cs" Inherits="Dropdownlist" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Asp.net dropdownlist control</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<td style="height: 45px"><asp:Label ID="Label1" runat="server" Style="left: -1px; position: relative; top: 0px"
Text="Name:" Width="46px"></asp:Label></td>
<td style="height: 45px"><asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource1"
DataTextField="EmpName" DataValueField="EmpName" Height="26px" Style="left: 3px;
position: relative; top: 0px" Width="125px">
<asp:ListItem> << Select >></asp:ListItem>
</asp:DropDownList></td>
<td style="height: 45px">
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:masterConnectionString %>"
SelectCommand="SELECT [EmpName] FROM [tbl_employee_profile]"></asp:SqlDataSource></td>
</tr>
</table>
<asp:DropDownList ID="DropDownList" runat="server">
</asp:DropDownList>
</div>
</form>
</body>
</html>source from my old blog: Readmore