private void barButtonItem_DMHuyen_ItemClick(object sender, ItemClickEventArgs e) { if (formDMHuyen == null) { formDMHuyen = new F_Main_DMHuyen(); formDMHuyen.MdiParent = this; formDMHuyen.FormClosed += new FormClosedEventHandler(formDMHuyen_FormClosed); formDMHuyen.Show(); } else { formDMHuyen.Activate(); } }
void formDMHuyen_FormClosed(object sender, FormClosedEventArgs e) { formDMHuyen = null; }