RibbonForm mdishow = new RibbonForm();  //实例化

            midshow.MdiParent = this;  //设置在主窗体，以MDI的方式显示，关键属性。

            mdishou.Show();//显示窗体

protected override CreateParams CreateParams  //解决MDI闪屏

        {

            get

            {

                CreateParams cp = base.CreateParams;

                cp.ExStyle |= 0x02000000;

                return cp;

            }

        }