关于tToolStripMenuItem控件调用类的问题

我定义了一个ItemClass类,我想在一个主窗体main中的tToolStripMenuItem控件调用他,能运行,但是功能不能实现,请帮忙解决一下
  private void Menu_Click(object sender, EventArgs e)
        {
          WinOperationClass P_Menu = new WinOperationClass(); 
            P_Menu.ShowForm((ToolStripMenuItem)sender, this);   
        }using System;
using System.Collections.Generic;
using System.Text;
using ITEM.teacher;
using System.Windows.Forms;
using System.IO;
namespace ITEM.ItemClass
{
    class WinOperationClass
    {        #region  控件中的项操作
        /// <summary>
        /// 执行“目录”控件中的项操作
        /// </summary>
        /// <param name="control">控件类型</param>
        /// <param name="form">所属窗体</param>
        public void ShowForm(ToolStripMenuItem control, Form form)
        {
            switch (control.Tag.ToString())
            {
                case "1":
                    TeacherInfo teacher = new TeacherInfo();
                    teacher.MdiParent = form;
                    teacher.StartPosition = FormStartPosition.CenterScreen;
                    teacher.Show();
                    break;
                   
                case "2":
                    owninfo oif = new owninfo();
                    oif.MdiParent = form;
                    oif.StartPosition = FormStartPosition.CenterScreen;
                    oif.Show();
                    break;
                   
                default:
                    break;
            }
        }     
        #endregion
    }