:master: ma ha senso una cosa del genere?

codice:
    Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreRender
        Dim g As GridView = Me.GridView1
        For Each r As GridViewRow In g.Controls(0).Controls
            r.Controls(9).Visible = False
        Next
nascondo la 10° colonna (indice 9)