/ file attributes
int hTemplateFile // handle to template file
);
[DllImport("kernel32.dll")]
private static extern bool GetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
[DllImport("kernel32.dll")]
private static extern bool BuildCommDCB(
string lpDef, // device-control string
ref DCB lpDCB // device-control block
);
[DllImport("kernel32.dll")]
private static extern bool SetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
[DllImport("kernel32.dll")]
private static extern bool GetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
[DllImport("kernel32.dll")]
private static extern bool SetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
[DllImport("kernel32.dll")]
private static extern bool ReadFile(
int hFile, // handle to file
byte[] lpBuffer, // data buffer
int nNumberOfBytesToRead, // number of bytes to read
ref int lpNumberOfBytesRead, // number of bytes read
ref OVERLAPPED lpOverlapped // overlapped buffer
);
[DllImport("kernel32.dll")]
private static extern bool WriteFile(
int hFile, // handle to file
byte[] lpBuffer, // data buffer
int nNumberOfBytesToWrite, // number of bytes to write
ref int lpNumberOfBytesWritten, // number of bytes written
ref OVERLAPPED lpOverlapped // overlapped buffer
);
[DllImport("kernel32.dll")]
private static extern bool CloseHandle(
int hObject // handle to object
);
public void Open()
{
DCB dcbCommPort = new DCB();
COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();
// OPEN THE COMM PORT.
hComm = CreateFile("COM" + PortNum ,GENERIC_READ | GENERIC_WRITE,0, 0,OPEN_EXISTING,0,0);
// IF THE PORT CANNOT BE OPENED, BAIL OUT.
if(hComm == INVALID_HANDLE_VALUE)
{
throw(new ApplicationException("Comm Port Can Not Be Opened"));
}
// SET THE COMM TIMEOUTS.
GetCommTimeouts(hComm,ref ctoCommPort);
ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;
ctoCommPort.ReadTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutConstant = 0;
SetCommTimeouts(hComm,ref ctoCommPort);
// SET BAUD RATE, PARITY, WORD SIZE, AND STOP BITS.
// THERE ARE OTHER WAYS OF DOING SETTING THESE BUT THIS IS THE EASIEST.
// IF YOU WANT TO LATER ADD CODE FOR OTHER BAUD RATES, REMEMBER
// THAT THE ARGUMENT FOR BuildCommDCB MUST BE A POINTER TO A STRING.
// ALSO NOTE THAT BuildCommDCB() DEFAULTS TO NO HANDSHAKING.
dcbCommPort.DCBlength = Marshal.SizeOf(dcbCommPort);
GetCommState(hComm, ref dcbCommPort);
dcbCommPort.BaudRate=BaudRate;
dcbCommPort.Parity=Parity;
dcbCommPort.ByteSize=ByteSize;
dcbCommPort.StopBits=StopBits;
SetCommState(hComm, ref dcbCommPort);
Opened = true;
}
public void Close()
{
if (hComm!=INVALID_HANDLE_VALUE)
{
CloseHandle(hComm);
Opened=false;
}
}
public byte[] Read(int NumBytes)
{
byte[] BufBytes;
byte[] OutBytes;
BufBytes = new byte[NumBytes];
if (hComm!=INVALID_HANDLE_VALUE)
{
OVERLAPPED ovlCommPort = new OV