private void GetCommStateNative(ref GWin32.DCB lpDcb)
{
int commErrors = 0;
GWin32.Comstat comStat = new GWin32.Comstat();
for (int i = 0; i < CommStateRetries; i++)
{
if (!GWin32.ClearCommError(m_Handle, ref commErrors, ref comStat))
{
WinIoError();
}
if (GWin32.GetCommState(m_Handle, ref lpDcb))
{
break;
}
if (i == CommStateRetries - 1)
{
WinIoError();
}
}
}
public void Open(string comPortName = "COM3", int baudRate = 128000)
{
if (m_hCommPort != null)
{
return;
}
SerialPort comm = new SerialPort();
comm.BaudRate = baudRate;
m_hCommPort = GWin32.CreateFile(comPortName,
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 == null || m_hCommPort.IsInvalid)
{
m_hCommPort = null;
int err = Marshal.GetLastWin32Error();
string errorMessage = new Win32Exception(Marshal.GetLastWin32Error()).Message;
if (onErr != null)
{
onErr.OnError("Open com failed " + errorMessage, true);
}
throwWinErr("Open com failed ");
}
const uint EV_RXCHAR = 1, EV_TXEMPTY = 4;
if (!GWin32.SetCommMask(m_hCommPort, EV_RXCHAR | EV_TXEMPTY))
{
if (onErr != null)
{
onErr.OnError("Failed to Set Comm Mask", true);
}
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))
{
if (onErr != null)
{
onErr.OnError("CSerialCommHelper : Failed to Get Comm State", true);
}
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))
{
if (onErr != null)
{
onErr.OnError("CSerialCommHelper : Failed to Get Comm State", true);
}
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);
}