private void btnTheLoai_Click(object sender, EventArgs e) { if (TL == null || TL.IsDisposed) { TL = new frmTheLoai(); TL.MdiParent = this; TL.Show(); } else { TL.Activate(); } }
private void btnTheLoai_Click(object sender, EventArgs e) { frmTheLoai TL = new frmTheLoai(); TL.Show(); }