[DllImport("kernel32.dll", EntryPoint = "DeviceIoControl", SetLastError = true)]

        internal static extern int DeviceIoControl(

            IntPtr hDevice,

            int dwIoControlCode,

            byte[] lpInBuffer,

            int nInBufferSize,

            byte[] lpOutBuffer,

            int nOutBufferSize,

            ref int lpBytesReturned,

            IntPtr lpOverlapped);



        [DllImport("kernel32.dll")]

        private static extern IntPtr CreateFile(

            string lpFileName,

            // 要打开的串口名称           

            uint dwDesiredAccess,

            // 指定串口的访问方式,一般设置为可读可写方式   

            int dwShareMode,

            // 指定串口的共享模式,串口不能共享,所以设置为0   

            int lpSecurityAttributes,

            // 设置串口的安全属性,WIN9X下不支持,应设为NULL   

            int dwCreationDisposition,

            // 对于串口通信,创建方式只能为OPEN_EXISTING   

             int dwFlagsAndAttributes,

            // 指定串口属性与标志,设置为FILE_FLAG_OVERLAPPED( 重叠I/O操作 ),指定串口以异步方式通信   

             int hTemplateFile

            // 对于串口通信必须设置为NULL   

        );



        private const uint GENERIC_READ = 0x80000000;

        private const uint GENERIC_WRITE = 0x40000000;

        private const int OPEN_EXISTING = 3;



        public Form1()

        {

            InitializeComponent();

        }



        private void GPIO测试_Load(object sender, EventArgs e)

        {



        }



        private void button1_Click(object sender, EventArgs e)

        {         

            IntPtr gpiodriver = CreateFile("GIO20:", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);

            、、就是这一句出错





            if (gpiodriver == (IntPtr)(-1))

            {

                MessageBox.Show("打开GPIO设备失败！");

            }

            else

            {



                int bytesReturned = 0;

                DeviceIoControl(gpiodriver, 0x01, null, 0, null, 0, ref bytesReturned, IntPtr.Zero);

            }

        }