private void Form1_Load(object sender, EventArgs e)
{
  //添加菜单一 
  ToolStripMenuItem subItem;
  subItem = AddContextMenu("入库", menuStrip1.Items, null);
  //添加子菜单 
  AddContextMenu("添加入库", subItem.DropDownItems, new EventHandler(MenuClicked));
  AddContextMenu("入库管理", subItem.DropDownItems, new EventHandler(MenuClicked));
  //添加菜单二 
  subItem = AddContextMenu("出库", menuStrip1.Items, null);
  //添加子菜单 
  AddContextMenu("添加出库", subItem.DropDownItems, new EventHandler(MenuClicked));
  AddContextMenu("出库管理", subItem.DropDownItems, new EventHandler(MenuClicked));
}
/// <summary>
/// 添加子菜单
/// </summary>
/// <param name="text">要显示的文字，如果为 - 则显示为分割线</param>
/// <param name="cms">要添加到的子菜单集合</param>
/// <param name="callback">点击时触发的事件</param>
/// <returns>生成的子菜单，如果为分隔条则返回null</returns>
ToolStripMenuItem AddContextMenu(string text, ToolStripItemCollection cms, EventHandler callback)
{
  if (text == "-")
  {
 ToolStripSeparator tsp = new ToolStripSeparator();
 cms.Add(tsp);
 return null;
  }
  else if (!string.IsNullOrEmpty(text))
  {
 ToolStripMenuItem tsmi = new ToolStripMenuItem(text);
 tsmi.Tag = text + "TAG";
 if (callback != null) tsmi.Click += callback;
 cms.Add(tsmi);
 return tsmi;
  }
  return null;
}
void MenuClicked(object sender, EventArgs e)
{
　　 　 //以下主要是动态生成事件并打开窗体
　　　　//((sender as ToolStripMenuItem).Tag)强制转换
  ObjectHandle t = Activator.CreateInstance("WinForms", "WinForms.Form2");
  Form f = (Form)t.Unwrap();
  f.ShowDialog();
}