private void AddBtn_Click(object sender, EventArgs e) { try { string obj = String.Format("{0}|{1}|{2}|{3}|{4}|{5}", nameSt.Text, numberSt.Text , _classSt.Text, boy.Checked, countrySt.Text, ageSt.Text); StudentVM.AddVM(obj); } catch (Exception er) { MessageBox.Show("Lỗi: " + er.Message); } render(); }