<!-- La griglia -->

<asp:PlaceHolder ID="videata_modifica" runat="server" visible="false">
<h2>Modifica news</h2>
<asp:DetailsView id="pannelloModifica" runat="server" AutoGenerateRows="false" 
OnItemUpdating="salvaModifiche"
>
<fields>
<asp:BoundField DataField="ID" HeaderText="ID" readOnly="true"><headerstyle ></asp:boundfield>
<asp:TemplateField HeaderText="Titolo">
<headerstyle CssClass="tblHeader" />
<EditItemTemplate>
<asp:TextBox id="m_titolo" ValidationGroup="modifica" Text='<%#Eval("Titolo")%>' columns="50" MaxLength="75" runat="server" />
<asp:RequiredFieldValidator ValidationGroup="modifica" Text=" *" runat="server" Display="Dynamic"
ControlToValidate="m_titolo" />
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Contenuto">
<headerstyle CssClass="tblHeader" />
<EditItemTemplate>
<asp:TextBox TextMode="MultiLine" rows="10" columns="60" id="m_contenuto" ValidationGroup="modifica" 
runat="server" Text='<%#Eval("Contenuto")%>' />
<asp:RequiredFieldValidator Display="Dynamic" Text=" *" ValidationGroup="modifica" ControlToValidate="m_contenuto" runat="server" />
</EditItemTemplate>
</asp:templatefield>
<asp:BoundField DataField="Autore" HeaderText="Autore"><headerstyle CssClass="tblHeader" /></asp:boundfield>
<asp:BoundField DataField="Data_Creazione" HeaderText="Data di creazione" readOnly="true"><headerstyle CssClass="tblHeader" /></asp:boundfield>
<asp:BoundField DataField="Data_UltimaModifica" HeaderText="Ultima modifica" readOnly="true"><headerstyle CssClass="tblHeader" /></asp:boundfield>
<asp:commandfield ShowEditButton="true" UpdateText="Salva" CancelText="Annulla" ValidationGroup="modifica" />
</fields>
</asp:DetailsView>
</asp:PlaceHolder>

void salvaModifiche(Object o, DetailsViewUpdateEventArgs e){
  risultato.Text = Convert.ToString(e.Keys.Count);
}

<asp:DetailsView id="pannelloModifica" runat="server" AutoGenerateRows="false" Width="80%"
DataKeyNames="ID" OnItemUpdating="salvaModifiche">

    videata_modifica.Visible = true;
    DataView dw = new DataView(dt);
    dw.RowFilter = "ID = " + dt.Rows[Convert.ToInt32(e.CommandArgument)]["ID"];
    pannelloModifica.DataSource = dw;
    pannelloModifica.ChangeMode(DetailsViewMode.Edit);
    pannelloModifica.DataBind();