Forms Data Controls :: Binding Formview - Update Personal Class When Change Textboxes And Click Update Button?

I have the follow form view:

<asp:FormView
DefaultMode="Edit"
ID="FormView1"
runat="server"
onitemupdating="FormView1_ItemUpdating">
<EditItemTemplate>
<asp:TextBox
ID="txtPrimerNombreNatural"
runat="server"
SkinID="texto"
MaxLength="30"
Text='<%#Bind("PrimerNombre") %>'></asp:TextBox>
<asp:TextBox
ID="txtSegundoNombreNatural"
runat="server"
SkinID="texto"
MaxLength="30"
Text='<%#Bind("SegundoNombre") %>'></asp:TextBox>
</EditItemTemplate>
</asp:FormView>
<asp:Button
ID="Actualizar"
runat="server"
Text="Button"
CommandName="Update"
/>
This formview is bound in this way:
protected void Page_Load(object sender,
EventArgs e)
{
Persona _persona =
new
Persona();
_persona.ObternerPersonaByUserIdApp(1);
List<SILPA.AccesoDatos.Generico.PersonaIdentity> persona =
new
List<SILPA.AccesoDatos.Generico.PersonaIdentity>();
persona.Add(_persona.Identity);
FormView1.DataSource = persona;
FormView1.DataBind();
}

When the page is shown, the textbox are filled correctly, this textbox are filled with the "primernombre" and "segundonombre" properties from the persona class. After this, If I change the textbox, and after click the update button, I need to update the persona class with the changes from the textboxes, then I call a ActualizarPersona method for updating the database. How can I do for update the persona class when I change the textboxes and click the update button? I try this method protected void FormView1_ItemUpdating(object sender, FormViewUpdateEventArgs
e)
{
}