private async void Button_Clicked(object sender, EventArgs e)
        {
            try
            {
                var name    = this.EntryName.Text;
                var desc    = this.EntryDescription.Text;
                var dataOra = this.EntryDate.Date;

                if (_item != null)
                {
                    ServerDataItem s = new ServerDataItem()
                    {
                        Id           = _item.Id,
                        Name         = name,
                        Description  = desc,
                        DataElemento = dataOra,
                    };

                    await _webApiProxy.Update(s);

                    await Navigation.PopAsync();
                }
                else
                {
                    // CREA NUOVO

                    ServerDataItem s = new ServerDataItem()
                    {
                        // Id = _item.Id,
                        Name         = name,
                        Description  = desc,
                        DataElemento = dataOra,
                    };

                    await _webApiProxy.Create(s);

                    await Navigation.PopAsync();
                }
            }
            catch (Exception ex)
            {
                await DisplayAlert("ERRORE", ex.Message, "OK");
            }
        }