c# - c#windows窗体子窗体前面显示MDI窗体的所有控件

Question

子窗体前面显示的MDI窗体的面板控件............

private void contentsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FormCollection fc = Application.OpenForms;
            foreach (Form frm in fc)
            {
                if (frm.Name.ToLower() == "frmshortcutkeys")
                {
                    return;
                }
            }
            frmShortcutKeys objfrmShortcutKeys = new frmShortcutKeys();
            objfrmShortcutKeys.MdiParent = this;
            objfrmShortcutKeys.Show();
        }