Protected Sub popolaDdl(ByVal sender As Object, ByVal e As EventArgs)
        Dim ddl As DropDownList = DirectCast(sender, DropDownList)
        'add an empty item on top of the list
        Dim fundb As New DataUtility.GenericDatabaseFunction
        Dim dt As New Data.DataTable
        dt = 'popolo dataTable
        For Each dtr As Data.DataRow In dt.Rows
            ddl.Items.Add(dtr("campoDb"))
        Next
End Sub

 <asp:TemplateField HeaderText="Tipo Attrezzatura">
                        <EditItemTemplate>
                            <asp:DropDownList ID="ddl1" AppendDataBoundItems="true" 
                            runat="server" AutoPostBack="True"  OnDataBound=popolaDdl>
                            <asp:ListItem Value="">Select an Item</asp:ListItem>
                            </asp:DropDownList>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="Label1" runat="server" Text='<%# Bind("Tipo_Attrezzatura")    %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>