动态生成多级菜单功能

http://topic.csdn.net/u/20101115/08/5b5786b3-856a-48d5-a41b-5b12783c645c.html

转贴过来：

  ToolStripDropDownButton dropBtn = new ToolStripDropDownButton();            dropBtn.DropDownItems.Add("000");            dropBtn.DropDownItems.Add("111");            foreach (ToolStripItem ts in dropBtn.DropDownItems)            {                ToolStripMenuItem item = ts as ToolStripMenuItem;                if (item != null && item.Text == "000")                {                    item.DropDownItems.Add("000-1");                    item.DropDownItems.Add("000-2");                    item.DropDownItems.Add("000-3");                    item.DropDownItems.Add("000-4");                    //more item                    break;                }            }