ASP.NET

    protected void GridView1_RowUpdating(object sender, GridViewUpdatedEventArgs e)
{
        string struName =(DropDownList)(GridView1.Rows[e.RowIndex].Cells[4].FindControl("Drop")).SelectedValue;
        e.NewValues["Active"] = struName;
       // e.Cancel = false; 

    }

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
    DataKeyNames="TransactionTypeID" DataSourceID="SqlDataSource3" 
    
        style="top: 345px; left: 390px; position: absolute; height: 133px; width: 187px; z-index: 1" 
        onrowupdated="GridView1_RowUpdating">
        <Columns>
            <asp:BoundField DataField="TransactionTypeID" HeaderText="TransactionTypeID" 
                ReadOnly="True" SortExpression="TransactionTypeID" />
            <asp:BoundField DataField="Transaction" HeaderText="Transaction" 
                SortExpression="Transaction" />
            <asp:BoundField DataField="Description" HeaderText="Description" 
                SortExpression="Description" />
            <asp:BoundField DataField="Category" HeaderText="Category" 
                SortExpression="Category" />
                <asp:TemplateField HeaderText="User Name"> 
            <ItemTemplate> 
<asp:Label ID="lbl1" runat="server" Text='<%# Bind("Active")%>' /> 
</ItemTemplate> 
<EditItemTemplate> 
<asp:DropDownList ID="Drop" runat="server" AppendDataBoundItems="true" 
 AutoPostBack="True" SelectedValue='<%# Bind("Active")%>'> 
<asp:ListItem Value="Yes"></asp:ListItem> 
<asp:ListItem Value ="No"></asp:ListItem>
</asp:DropDownList> 
</EditItemTemplate> 
</asp:TemplateField> 

        </Columns>
</asp:GridView>

<?xml version="1.0" encoding="utf-8" ?>
<StructureMap>
  <Assembly Name="MyCompany.MySite.Core" />
  <Assembly Name="MyCompany.MySite.Web" />
  <PluginFamily Assembly="MyCompany.MySite.Core" Type="MyCompany.MySite.Core.Impl.IRedirector" DefaultKey="Default"/>
</StructureMap>

namespace MyCompany.MySite.Core.Impl
{
    [PluginFamily("Default")]
    public interface IRedirector
    {
        /// <summary>
        ///     Sends the user to the home page.
        /// </summary>
        void GoToHomePage();

        /// <summary>
        ///     Sends the user to the error page.
        /// </summary>
        void GoToErrorPage();
    }
}

using MyCompany.MySite.Core;

namespace MyCompany.MySite.Web
{
     public class Global : System.Web.HttpApplication
     {
          protected void Application_Error(object sender, EventArgs e)
        {
            IRedirector redir = ObjectFactory.GetInstance<IRedirector>();
            redir.GoToErrorPage();
        }
     }
}