private void BtnSave_Click(object sender, EventArgs e) { if (edtNumber.Text != null) { var save = Service.AddCopy(int.Parse(edtNumber.Text), libro.Id); if (save.band) { Toast.MakeText(this, save.message, ToastLength.Long).Show(); edtISBN.Text = ""; edtNumber.Text = ""; edtTitulo.Text = ""; } else { Toast.MakeText(this, save.message, ToastLength.Long).Show(); } } else { Toast.MakeText(this, "Ingrese el número de copia", ToastLength.Long).Show(); } }