Change GridView SortDirection Default

Problem
Need to change the default SortDirection in a GridView for certain columns from ascending to descending.

Solution
Note: This was tested and implemented in ASP.NET 2.0.

  
<asp:GridView DataSourceID="MySqlDataSource" AllowSorting="true" AutoGenerateColumns="false" 
      ID="MainGridView" runat="server" OnSorting="MainGridView_Sorting">
      <Columns>
            <asp:BoundField DataField="MyDataField01" SortExpression="MyDataField01" />
            <asp:BoundField DataField="MyDataField02" SortExpression="MyDataField02" />
            <asp:BoundField DataField="MyDataField03" SortExpression="MyDataField03" />
            <asp:BoundField DataField="MyDataField04" SortExpression="MyDataField04" />
            <asp:BoundField DataField="MyDataField05" SortExpression="MyDataField05" />
            <asp:BoundField DataField="MyDataField06" SortExpression="MyDataField06" />
      </Columns>
</asp:GridView>
 
protected void MainGridView_Sorting(object sender, GridViewSortEventArgs e)
{
      // Change default sort order to Descending for certain columns.
      switch (e.SortExpression)
      {
            case "MyDataField01":
            case "MyDataField03":
            case "MyDataField06":
                  // Current sort column is different than previous sort column
                  if (e.SortExpression != MainGridView.SortExpression)
                  {
                        e.SortDirection = SortDirection.Descending;
                  }
                  break;
            default:
                  break;
      }
}