public static FrmCarton GetSingleton() { if (frm == null || frm.IsDisposed) { frm = new FrmCarton(); } return(frm); }
private void tsmiCarton_Click(object sender, EventArgs e) { FrmCarton frm = FrmCarton.GetSingleton(); frm.MdiParent = this; frm.Show(); frm.Activate(); }