/// <summary>

         /// 显示form

         /// </summary>

         /// <param name="form">要显示的form</param>

         /// <param name="canClose">是否将其他form关闭</param>

         private void ShowForm(Form form, bool canClose)

         {

             foreach (Form mdiChild in MdiChildren)

             {

                 bool b = mdiChild.GetType() == form.GetType();

                 if (b)

                 {

                     form.Close();

                     mdiChild.Focus();

                     return;

                 }

                 if (canClose)

                 {

                     mdiChild.Close();

                 }

             }

             form.MdiParent = this;

             form.ControlBox = false;

             form.WindowState = FormWindowState.Maximized;

             form.Show();

         }