void Reload()
{
dao = new SinhVienDAO();
dataGridDanhSachSV.ItemsSource = null;
dataGridDanhSachSV.ItemsSource = dao.GetSinhViens();
dataGridDanhSachSV.Items.Refresh();
}
private void BtnThemSV_Click(object sender, RoutedEventArgs e)
{
NhapSV nhapSV = new NhapSV();
nhapSV.ShowInTaskbar = false;
nhapSV.Owner = this;
nhapSV.ShowDialog();
dataGridDanhSachSV.ItemsSource = dao.GetSinhViens();
Reload();
}