主窗体嵌套子窗体方法，可直接引用

/// <summary>

 /// 在主窗体中嵌套子窗体，主窗体中的 IsMdicontainer 设置成True;         /// </summary>         /// <param name="p">Panael</param>         /// <param name="F">子窗体</param>

 private  void AddForm(Panel p, Form F)         {             foreach (Control item in p.Controls)             {                 if (item is Form)                 {                     ((Form)item).Close();                 }             }                       F.MdiParent = this;             F.Parent = p;             F.FormBorderStyle = FormBorderStyle.None;             F.Show();         }