private void KiêuTrả_Click(object sender, EventArgs e) { if (KieuTrafrm == null || KieuTrafrm.IsDisposed) { KieuTrafrm = new frmKieuTra(); KieuTrafrm.MdiParent = this; KieuTrafrm.Show(); } else { KieuTrafrm.Activate(); } }
private void btnThemkieutra_Click(object sender, EventArgs e) { frmKieuTra KT = new frmKieuTra(); KT.ShowDialog(); }