Вот пример из документации вижуал студии. (там еще другие есть примеры - набери DetailsView class)
<%@ Page Language="C#" %>
<html>
<body>
<form runat="server">
<div>
<table>
<tr>
<td>
<asp:GridView ID="GridView1" runat="server"
AutoGenerateColumns="False" DataSourceID="Customers"
DataKeyNames="CustomerID">
<Columns>
<asp:CommandField ShowSelectButton="True" />
<asp:BoundField DataField="ContactName" HeaderText="ContactName" />
<asp:BoundField DataField="CompanyName" HeaderText="CompanyName" />
</Columns>
</asp:GridView>
</td>
<td valign="top">
<asp:DetailsView ID="DetailsView1" runat="server"
AutoGenerateRows="True" DataKeyNames="CustomerID"
DataSourceID="Details" Height="50px" Width="301px">
</asp:DetailsView>
</td>
</tr>
</table>
<asp:SqlDataSource ID="Details" runat="server"
ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
SelectCommand="SELECT * FROM [Customers] WHERE ([CustomerID] = @CustomerID)">
<SelectParameters>
<asp:ControlParameter ControlID="GridView1" Name="CustomerID"
PropertyName="SelectedValue"
Type="String" />
</SelectParameters>
</asp:SqlDataSource>
<asp:SqlDataSource ID="Customers" runat="server"
ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
SelectCommand="SELECT [CompanyName], [ContactName], [CustomerID] FROM [Customers]">
</asp:SqlDataSource>
</div>
</form>
</body>
</html>
