Summary:
The DCB structure defines the control setting for a serial communications device.
// Able to handle C++ BitFlags.
using System.Collections.Specialized;
using System.Runtime.InteropServices;
[StructLayout(LayoutKind.Sequential)]
internal struct Dcb
{
internal uint DCBLength;
internal uint BaudRate;
private BitVector32 Flags;
//I've missed some members...
private uint wReserved; // not currently used
internal uint XonLim; // transmit XON threshold
internal uint XoffLim; // transmit XOFF threshold
internal byte ByteSize;
internal Parity Parity;
internal StopBits StopBits;
//...and some more
internal char XonChar; // Tx and Rx XON character
internal char XoffChar; // Tx and Rx XOFF character
internal char ErrorChar; // error replacement character
internal char EofChar; // end of input character
internal char EvtChar; // received event character
private uint wReserved1; // reserved; do not use
private static readonly int fBinary;
private static readonly int fParity;
private static readonly int fOutxCtsFlow;
private static readonly int fOutxDsrFlow;
private static readonly BitVector32.Section fDtrControl;
private static readonly int fDsrSensitivity;
private static readonly int fTXContinueOnXoff;
private static readonly int fOutX;
private static readonly int fInX;
private static readonly int fErrorChar;
private static readonly int fNull;
private static readonly BitVector32.Section fRtsControl;
private static readonly int fAbortOnError;
static Dcb()
{
// Create Boolean Mask
int previousMask;
fBinary = BitVector32.CreateMask();
fParity = BitVector32.CreateMask(fBinary);
fOutxCtsFlow = BitVector32.CreateMask(fParity);
fOutxDsrFlow = BitVector32.CreateMask(fOutxCtsFlow);
previousMask = BitVector32.CreateMask(fOutxDsrFlow);
previousMask = BitVector32.CreateMask(previousMask);
fDsrSensitivity = BitVector32.CreateMask(previousMask);
fTXContinueOnXoff = BitVector32.CreateMask(fDsrSensitivity);
fOutX = BitVector32.CreateMask(fTXContinueOnXoff);
fInX = BitVector32.CreateMask(fOutX);
fErrorChar = BitVector32.CreateMask(fInX);
fNull = BitVector32.CreateMask(fErrorChar);
previousMask = BitVector32.CreateMask(fNull);
previousMask = BitVector32.CreateMask(previousMask);
fAbortOnError = BitVector32.CreateMask(previousMask);
// Create section Mask
BitVector32.Section previousSection;
previousSection = BitVector32.CreateSection(1);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
fDtrControl = BitVector32.CreateSection(2, previousSection);
previousSection = BitVector32.CreateSection(1, fDtrControl);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
previousSection = BitVector32.CreateSection(1, previousSection);
fRtsControl = BitVector32.CreateSection(3, previousSection);
previousSection = BitVector32.CreateSection(1, fRtsControl);
}
public bool Binary
{
get { return Flags[fBinary]; }
set { Flags[fBinary] = value; }
}
public bool CheckParity
{
get { return Flags[fParity]; }
set { Flags[fParity] = value; }
}
public bool OutxCtsFlow
{
get { return Flags[fOutxCtsFlow]; }
set { Flags[fOutxCtsFlow] = value; }
}
public bool OutxDsrFlow
{
get { return Flags[fOutxDsrFlow]; }
set { Flags[fOutxDsrFlow] = value; }
}
public DtrControl DtrControl
{
get { return (DtrControl)Flags[fDtrControl]; }
set { Flags[fDtrControl] = (int)value; }
}
public bool DsrSensitivity
{
get { return Flags[fDsrSensitivity]; }
set { Flags[fDsrSensitivity] = value; }
}
public bool TxContinueOnXoff
{
get { return Flags[fTXContinueOnXoff]; }
set { Flags[fTXContinueOnXoff] = value; }
}
public bool OutX
{
get { return Flags[fOutX]; }
set { Flags[fOutX] = value; }
}
public bool InX
{
get { return Flags[fInX]; }
set { Flags[fInX] = value; }
}
public bool ReplaceErrorChar
{
get { return Flags[fErrorChar]; }
set { Flags[fErrorChar] = value; }
}
public bool Null
{
get { return Flags[fNull]; }
set { Flags[fNull] = value; }
}
public RtsControl RtsControl
{
get { return (RtsControl)Flags[fRtsControl]; }
set { Flags[fRtsControl] = (int)value; }
}
public bool AbortOnError
{
get { return Flags[fAbortOnError]; }
set { Flags[fAbortOnError] = value; }
}
}
Private Type DCB
DCBlength As Long
BaudRate As Long
fBitFields As Long 'See Comments in Win32API.Txt
wReserved As Integer
XonLim As Integer
XoffLim As Integer
ByteSize As Byte
Parity As Byte
StopBits As Byte
XonChar As Byte
XoffChar As Byte
ErrorChar As Byte
EofChar As Byte
EvtChar As Byte
wReserved1 As Integer 'Reserved; Do Not Use
End Type
Note there is a Microsoft KB Artcile describing how to access serial and parallel ports in VB.NET
http://support.microsoft.com/default.aspx?scid=kb;en-us;823179&Product=vb6
Here is the structure - worked for me:
Public Structure DCB
Public DCBlength As Int32
Public BaudRate As Int32
Public fBitFields As Int32
Public wReserved As Int16
Public XonLim As Int16
Public XoffLim As Int16
Public ByteSize As Byte
Public Parity As Byte
Public StopBits As Byte
Public XonChar As Byte
Public XoffChar As Byte
Public ErrorChar As Byte
Public EofChar As Byte
Public EvtChar As Byte
Public wReserved1 As Int16 'Reserved; Do Not Use
End Structure
None.
Special thanks to Jay's Outlook MVP from Visual C# Community for the guidance.
fDtrControl = BitVector32.CreateSection(2, previousSection);
fRtsControl = BitVector32.CreateSection(3, previousSection);
You will notice that fDtrControl expects 2 and fRtsControl expect 3. Why?
The reason is that the highest value within enum DtrControl is 2, and highest valye within enum RtsControl is 3.
This helps you to fix the bitflag issue in c to c#. I had tested it and it works greatly.
To use this code,
Example:
C#
Dcb myDcb = new Dcb();
myDcb.Binary = true;
myDcb.DtrControl = DtrControl.Disable; // DtrControl is an enum