private void OpenedFrm(Form FrmCls) { int i = 0; int j = 0; for (i = 0; i < MdiChildren.Length; i++) { if (MdiChildren[i].Name == FrmCls.Name) { j++; break; } } if (j == 0) { FrmCls.MdiParent = this; FrmCls.Show(); FrmCls.WindowState = FormWindowState.Maximized; } else { MdiChildren[i].Activate(); } } 转载于:https://www.cnblogs.com/zhahost/archive/2008/06/02/1212398.html