I'm running into a thing with a data edit WebForm trying to set a column's ReadOnly property.

Data is returned from SQL into a DataSet

GridView is defined as follows

   asp:GridView ID="GV1" runat="server" AutoGenerateEditButton="True" 
        CellPadding="10" CellSpacing="10" BorderStyle="Solid" 
        HorizontalAlign="Center" Caption="DashBoard Configuration Settings" 
        CaptionAlign="Top">
        EditRowStyle BackColor="#99CCFF" />
    /asp:GridView>

GridView GV1 is handled as follows

GV1.DataSource = GVSet;
GV1.DataBind()

The data displays in a grid, as one would expect, but when I get the ColumnIndex of the column that should be ReadOnly and then try to set it with
((BoundField)GV1.Columns[ColIndx]).ReadOnly = true;

I get an "index out of bounds" error because GV1.Columns.Count = 0

What am I missing, besides a deep and abiding understanding of c#?