public void Open()
{
if (m_hCommPort != IntPtr.Zero)
{
return;
}
SerialPort comm = new SerialPort();
comm.BaudRate = 128000;
m_hCommPort = GWin32.CreateFile("COM3",
FileAccess.Read | FileAccess.Write, //GENERIC_READ | GENERIC_WRITE,//access ( read and write)
FileShare.None, //0, //(share) 0:cannot share the COM port
IntPtr.Zero, //0, //security (None)
FileMode.Open, //OPEN_EXISTING,// creation : open_existing
0x20000000 | 0x40000000, //FILE_FLAG_OVERLAPPED,// we want overlapped operation
IntPtr.Zero //0// no templates file for COM port...
);
if (m_hCommPort == IntPtr.Zero)
{
int err = Marshal.GetLastWin32Error();
string errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
throwWinErr("Open com failed ");
}
const uint EV_RXCHAR = 1, EV_TXEMPTY = 4;
if (!GWin32.SetCommMask(m_hCommPort, EV_RXCHAR | EV_TXEMPTY))
{
throwWinErr("Failed to Set Comm Mask");
}
GWin32.DCB dcb = new GWin32.DCB();
dcb.DCBLength = (uint)Marshal.SizeOf(dcb);
if (!GWin32.GetCommState(m_hCommPort, ref dcb))
{
throwWinErr("CSerialCommHelper : Failed to Get Comm State");
}
dcb.BaudRate = (uint)comm.BaudRate;
dcb.ByteSize = (byte)comm.DataBits;
dcb.Parity = comm.Parity;
dcb.StopBits = comm.StopBits;
dcb.DsrSensitivity = false;
dcb.DtrControl = GWin32.DtrControl.Enable;
dcb.OutxDsrFlow = false;
dcb.OutxCtsFlow = false;
dcb.InX = false;
dcb.RtsControl = GWin32.RtsControl.Disable;
dcb.Binary = true;
if (!GWin32.SetCommState(m_hCommPort, ref dcb))
{
throwWinErr("CSerialCommHelper : Failed to Set Comm State");
}
GWin32.COMMTIMEOUTS commTimeouts = new GWin32.COMMTIMEOUTS();
commTimeouts.ReadIntervalTimeout = 0; // Never timeout, always wait for data.
commTimeouts.ReadTotalTimeoutMultiplier = 0; // Do not allow big read timeout when big read buffer used
commTimeouts.ReadTotalTimeoutConstant = 0; // Total read timeout (period of read loop)
commTimeouts.WriteTotalTimeoutConstant = 0; // Const part of write timeout
commTimeouts.WriteTotalTimeoutMultiplier = 0; // Variable part of write timeout (per byte)
GWin32.SetCommTimeouts(m_hCommPort, ref commTimeouts);
}
protected void SetTimeout(uint tm = GWin32.INFINITE)
{
GWin32.COMMTIMEOUTS commTimeouts = new GWin32.COMMTIMEOUTS();
commTimeouts.ReadIntervalTimeout = tm;
GWin32.SetCommTimeouts(m_hCommPort, ref commTimeouts);
}