Dev的DocumentManager添加窗体

1.DocumentManager要设置自己的MdiParent属性

2.主窗体设置IsMidContainer为True

3.要生成的窗体设置MdiParent为主窗体

4.正常创建窗体，然后就可以显示..Show()

            Form formscene = new Form();
            formscene.Name = Guid.NewGuid() + "";
            formscene.Text = "test";
            formscene.Dock = DockStyle.Fill;
            formscene.MdiParent = this;
            formscene.Show();