void menuPlugin_Demo2_DropDownOpening(object sender, EventArgs e) { ToolStripMenuItem menuPlugin_Demo2 = sender as ToolStripMenuItem; menuPlugin_Demo2.DropDownItems.Clear(); for (int i = 0; i < 10; ++i) { // 定义了一个子类用来传参数 IntMenuItem menuPlugin_Demo2_N = new IntMenuItem(i); menuPlugin_Demo2.DropDownItems.Add(menuPlugin_Demo2_N); menuPlugin_Demo2_N.Click += menuPlugin_Demo2_N_Click; } }