asp.net making a gridView column invisible - asp.net

Question

This is a Master-Detail form. Master is a GridView. And, the Detail is a DetailsView.
The entire thing is achieved programmatically.
As you can see from the code, DetailsView is using the Master-objects's ID to retrieve the Detail items.
I need to make the ID column of the Master-GridView invisible. Coz, it is irrelevent for the user of the page. But it must not harm the page logic.
But the code-line, GridView1.Columns[1].Visible = false; is generating an exception.
Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
How should I solve this problem?
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindData();
}
}
protected void BindData()
{
List<Order> orders = Order.Get();
GridView1.DataSource = orders;
GridView1.DataBind();
// This is giving Error...............!!!
GridView1.Columns[1].Visible = false;
// At first, when the page first loads,
// GridView1.SelectedIndex == -1
// So, this is done to automatically select the 1st item.
if (GridView1.SelectedIndex < 0)
{
GridView1.SelectedIndex = 0;
}
int selRowIndex = GridView1.SelectedIndex;
int selMasterId = Convert.ToInt32(GridView1.Rows[selRowIndex].Cells[1].Text);
Order master = Order.Get(selMasterId);
labItemsCount.Text = master.Items.Count.ToString();
DetailsView1.DataSource = master.Items;
DetailsView1.DataBind();
}
protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
BindData();
}
protected void DetailsView1_PageIndexChanging(object sender, DetailsViewPageEventArgs e)
{
DetailsView1.PageIndex = e.NewPageIndex;
BindData();
}
}

Answer 1

Have you considered using the DataKeyNames property of the gridview? This way you can remove the 'id' column from the GridView bu still access the 'id' value in the Page_Load.
DataKeyNames = "id"
Then you can get the value of the id like this.
int selRowIndex = GridView1.SelectedIndex;
int selMasterId = Convert.ToInt32(GridView.DataKeys[selRowIndex].Value);
Order master = Order.Get(selMasterId);
Alternately, you could try changing the visibility of the column in the OnRowBound event of the GridView.
protected void GridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.Header ||
e.Row.RowType == DataControlRowType.DataRow ||
e.Row.RowType == DataControlRowType.Footer)
{
e.Row.Cells[1].Visible = false;
}
}