Enabling Automatic PostBacks : DropDownList « Data Binding « ASP.NET Tutorial
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- Data Binding
- DropDownList
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<script runat="server">
protected void ddlProducts_SelectedIndexChanged(object sender, EventArgs e)
{
lblSelectedProduct.Text = ddlProducts.SelectedItem.Text;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>AutoPostBack List Control</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DropDownList
id="ddlProducts"
DataSourceID="srcProducts"
DataTextField="Title"
DataValueField="Id"
AutoPostBack="true"
OnSelectedIndexChanged="ddlProducts_SelectedIndexChanged"
Runat="server" />
<br /><br />
<asp:Label
id="lblSelectedProduct"
Runat="server" />
<asp:SqlDataSource
id="srcProducts"
SelectCommand="SELECT Id, Title FROM Products"
ConnectionString="<%$ ConnectionStrings:Products %>"
Runat="server" />
</div>
</form>
</body>
</html>
File: Web.config
<configuration>
<connectionStrings>
<add name="Products"
connectionString="Data Source=.\SQLEXPRESS;
AttachDbFilename=|DataDirectory|MyDatabase.mdf;Integrated Security=True;User Instance=True" />
</connectionStrings>
</configuration>