使用API函数发送消息关闭程序：WM_CLOSE=0x0010;

        private void button1_Click(object sender, EventArgs e)        {            //使用API函数发送消息关闭程序：WM_CLOSE=0x0010;            SendMessage(System.Diagnostics.Process.GetCurrentProcess().MainWindowHandle, 0x0010, 0, 0);        }        [System.Runtime.InteropServices.DllImport("user32")]        private static extern Int16 SendMessage(IntPtr hWnd, Int16 Msg, Int16 wParam, Int16 lParam);