public Int32 ReadCom(byte[] toSend, int uiCount)
{
bool bRes = false, bComEvent;
UInt32 retlen;
bComEvent = Win32Com.SetCommMask(_hPort, EV_RXCHAR);
if (bComEvent)
{
bRes = ReadFile(_hPort, // handle of file to read
toSend, // pointer to buffer that receives data
(uint)uiCount, // number of bytes to read
out retlen, // pointer to number of bytes read
IntPtr.Zero // pointer to structure for data
);
if (!(bRes))
{
return(0);
}
if (retlen > 0) //If we have data
{
return((Int32)retlen); //return the length
}
else
{
return(0); //else no data has been read
}
}
else
{
return(0);
}
}
private void ReceiveThread()
{
var buf = new Byte[1];
var sg = new AutoResetEvent(false);
var ov = new OVERLAPPED();
var unmanagedOv = Marshal.AllocHGlobal(Marshal.SizeOf(ov));
ov.Offset = 0; ov.OffsetHigh = 0;
ov.hEvent = sg.Handle;
Marshal.StructureToPtr(ov, unmanagedOv, true);
uint eventMask = 0;
var uMask = Marshal.AllocHGlobal(Marshal.SizeOf(eventMask));
try
{
while (true)
{
if (!Win32Com.SetCommMask(_hPort, Win32Com.EV_RXCHAR | Win32Com.EV_TXEMPTY | Win32Com.EV_CTS | Win32Com.EV_DSR
| Win32Com.EV_BREAK | Win32Com.EV_RLSD | Win32Com.EV_RING | Win32Com.EV_ERR))
{
throw new CommPortException("IO Error [001]");
}
Marshal.WriteInt32(uMask, 0);
if (!Win32Com.WaitCommEvent(_hPort, uMask, unmanagedOv))
{
if (Marshal.GetLastWin32Error() == Win32Com.ERROR_IO_PENDING)
{
sg.WaitOne();
}
else
{
throw new CommPortException("IO Error [002]");
}
}
eventMask = (uint)Marshal.ReadInt32(uMask);
if ((eventMask & Win32Com.EV_ERR) != 0)
{
UInt32 errs;
if (Win32Com.ClearCommError(_hPort, out errs, IntPtr.Zero))
{
var s = new StringBuilder("UART Error: ", 40);
if ((errs & Win32Com.CE_FRAME) != 0)
{
s = s.Append("Framing,");
}
if ((errs & Win32Com.CE_IOE) != 0)
{
s = s.Append("IO,");
}
if ((errs & Win32Com.CE_OVERRUN) != 0)
{
s = s.Append("Overrun,");
}
if ((errs & Win32Com.CE_RXOVER) != 0)
{
s = s.Append("Receive Cverflow,");
}
if ((errs & Win32Com.CE_RXPARITY) != 0)
{
s = s.Append("Parity,");
}
if ((errs & Win32Com.CE_TXFULL) != 0)
{
s = s.Append("Transmit Overflow,");
}
s.Length = s.Length - 1;
throw new CommPortException(s.ToString());
}
throw new CommPortException("IO Error [003]");
}
if ((eventMask & Win32Com.EV_RXCHAR) != 0)
{
uint gotbytes;
do
{
if (!Win32Com.ReadFile(_hPort, buf, 1, out gotbytes, unmanagedOv))
{
if (Marshal.GetLastWin32Error() == Win32Com.ERROR_IO_PENDING)
{
Win32Com.CancelIo(_hPort);
gotbytes = 0;
}
else
{
throw new CommPortException("IO Error [004]");
}
}
if (gotbytes == 1)
{
OnRxChar(buf[0]);
}
} while (gotbytes > 0);
}
if ((eventMask & Win32Com.EV_TXEMPTY) != 0)
{
OnTxDone();
}
if ((eventMask & Win32Com.EV_BREAK) != 0)
{
OnBreak();
}
uint i = 0;
if ((eventMask & Win32Com.EV_CTS) != 0)
{
i |= Win32Com.MS_CTS_ON;
}
if ((eventMask & Win32Com.EV_DSR) != 0)
{
i |= Win32Com.MS_DSR_ON;
}
if ((eventMask & Win32Com.EV_RLSD) != 0)
{
i |= Win32Com.MS_RLSD_ON;
}
if ((eventMask & Win32Com.EV_RING) != 0)
{
i |= Win32Com.MS_RING_ON;
}
if (i != 0)
{
uint f;
if (!Win32Com.GetCommModemStatus(_hPort, out f))
{
throw new CommPortException("IO Error [005]");
}
OnStatusChange(new ModemStatus(i), new ModemStatus(f));
}
}
}
catch (Exception e)
{
if (uMask != IntPtr.Zero)
{
Marshal.FreeHGlobal(uMask);
}
if (unmanagedOv != IntPtr.Zero)
{
Marshal.FreeHGlobal(unmanagedOv);
}
if (!(e is ThreadAbortException))
{
_rxException = e;
OnRxException(e);
}
}
}