C#封装的一个串口操作类（可用于Win CE）

using System;
using System.Runtime.InteropServices;

namespace NativeDll
{
/// <summary>
/// SerialPort 的摘要说明。
/// </summary>
public class SerialPort
{
#region 申明要引用的和串口调用有关的API
//win32 api constants
private const uint GENERIC_READ = 0x80000000;
private const uint GENERIC_WRITE = 0x40000000;
private const int OPEN_EXISTING = 3;
private const int INVALID_HANDLE_VALUE = -1;
private const int MAXBLOCK = 4096;

private const uint PURGE_TXABORT = 0x0001; // Kill the pending/current writes to the comm port.
private const uint PURGE_RXABORT = 0x0002; // Kill the pending/current reads to the comm port.
private const uint PURGE_TXCLEAR = 0x0004; // Kill the transmit queue if there.
private const uint PURGE_RXCLEAR = 0x0008; // Kill the typeahead buffer if there.

[StructLayout(LayoutKind.Sequential)]
private struct DCB
{
//taken from c struct in platform sdk
public int DCBlength; // sizeof(DCB)
public int BaudRate; // current baud rate
public int fBinary; // binary mode, no EOF check
public int fParity; // enable parity checking
public int fOutxCtsFlow; // CTS output flow control
public int fOutxDsrFlow; // DSR output flow control
public int fDtrControl; // DTR flow control type
public int fDsrSensitivity; // DSR sensitivity
public int fTXContinueOnXoff; // XOFF continues Tx
public int fOutX; // XON/XOFF out flow control
public int fInX; // XON/XOFF in flow control
public int fErrorChar; // enable error replacement
public int fNull; // enable null stripping
public int fRtsControl; // RTS flow control
public int fAbortOnError; // abort on error
public int fDummy2; // reserved
public ushort wReserved; // not currently used
public ushort XonLim; // transmit XON threshold
public ushort XoffLim; // transmit XOFF threshold
public byte ByteSize; // number of bits/byte, 4-8
public byte Parity; // 0-4=no,odd,even,mark,space
public byte StopBits; // 0,1,2 = 1, 1.5, 2
public char XonChar; // Tx and Rx XON character
public char XoffChar; // Tx and Rx XOFF character
public char ErrorChar; // error replacement character
public char EofChar; // end of input character
public char EvtChar; // received event character
public ushort wReserved1; // reserved; do not use
}

[StructLayout(LayoutKind.Sequential)]
private struct COMMTIMEOUTS
{
public int ReadIntervalTimeout;
public int ReadTotalTimeoutMultiplier;
public int ReadTotalTimeoutConstant;
public int WriteTotalTimeoutMultiplier;
public int WriteTotalTimeoutConstant;
}

[StructLayout(LayoutKind.Sequential)]
private struct OVERLAPPED
{
public int Internal;
public int InternalHigh;
public int Offset;
public int OffsetHigh;
public int hEvent;
}

[StructLayout(LayoutKind.Sequential)]
private struct COMSTAT
{
/*public int fCtsHold;
public int fDsrHold;
public int fRlsdHold;
public int fXoffHold;
public int fXoffSent;
public int fEof;
public int fTxim;
public int fReserved;
public int cbInQue;
public int cbOutQue;*/
// Should have a reverse, i don't know why!!!!!
public int cbOutQue;
public int cbInQue;
public int fReserved;
public int fTxim;
public int fEof;
public int fXoffSent;
public int fXoffHold;
public int fRlsdHold;
public int fDsrHold;
public int fCtsHold;
}
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern int CreateFile(
string lpFileName, // file name
uint dwDesiredAccess, // access mode
int dwShareMode, // share mode
int lpSecurityAttributes, // SD
int dwCreationDisposition, // how to create
int dwFlagsAndAttributes, // file attributes
int hTemplateFile // handle to template file
);
#else
[DllImport("coredll")]
private static extern int CreateFile(
string lpFileName, // file name
uint dwDesiredAccess, // access mode
int dwShareMode, // share mode
int lpSecurityAttributes, // SD
int dwCreationDisposition, // how to create
int dwFlagsAndAttributes, // file attributes
int hTemplateFile // handle to template file
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool GetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
#else
[DllImport("coredll")]
private static extern bool GetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool BuildCommDCB(
string lpDef, // device-control string
ref DCB lpDCB // device-control block
);
#else
[DllImport("coredll")]
private static extern bool BuildCommDCB(
string lpDef, // device-control string
ref DCB lpDCB // device-control block
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool SetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
#else
[DllImport("coredll")]
private static extern bool SetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool GetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
#else
[DllImport("coredll")]
private static extern bool GetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool SetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
#else
[DllImport("coredll")]
private static extern bool SetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
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
);
#else
[DllImport("coredll")]
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
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
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
);
#else
[DllImport("coredll")]
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
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool CloseHandle(
int hObject // handle to object
);
#else
[DllImport("coredll")]
private static extern bool CloseHandle(
int hObject // handle to object
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool ClearCommError(
int hFile, // handle to file
ref int lpErrors,
ref COMSTAT lpStat
);
#else
[DllImport("coredll")]
private static extern bool ClearCommError(
int hFile, // handle to file
ref int lpErrors,
ref COMSTAT lpStat
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool PurgeComm(
int hFile, // handle to file
uint dwFlags
);
#else
[DllImport("coredll")]
private static extern bool PurgeComm(
int hFile, // handle to file
uint dwFlags
);
#endif
#if FULLFRAMEWORK
[DllImport("kernel32")]
private static extern bool SetupComm(
int hFile,
int dwInQueue,
int dwOutQueue
);
#else
[DllImport("coredll")]
private static extern bool SetupComm(
int hFile,
int dwInQueue,
int dwOutQueue
);
#endif
#endregion

// SerialPort的成员变量
private int hComm = INVALID_HANDLE_VALUE;
private bool bOpened = false;

public bool Opened
{
get
{
return bOpened;
}
}

/// <summary>
///串口的初始化函数
///lpFileName 端口名
///baudRate 波特率
///parity 校验位
///byteSize 数据位
///stopBits 停止位
/// <summary>
public bool OpenPort(string lpFileName,int baudRate,byte parity, byte byteSize, byte stopBits)
{
// OPEN THE COMM PORT.
hComm = CreateFile(lpFileName ,GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
// IF THE PORT CANNOT BE OPENED, BAIL OUT.
if(hComm == INVALID_HANDLE_VALUE)
{
return false;
}

SetupComm(hComm, MAXBLOCK, MAXBLOCK);

// SET THE COMM TIMEOUTS.
COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();
GetCommTimeouts(hComm,ref ctoCommPort);
ctoCommPort.ReadIntervalTimeout = Int32.MaxValue;
ctoCommPort.ReadTotalTimeoutConstant = 0;
ctoCommPort.ReadTotalTimeoutMultiplier = 0;
ctoCommPort.WriteTotalTimeoutMultiplier = 10;
ctoCommPort.WriteTotalTimeoutConstant = 1000;
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.
DCB dcbCommPort = new DCB();
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);

PurgeComm(hComm, PURGE_RXCLEAR | PURGE_RXABORT);
PurgeComm(hComm, PURGE_TXCLEAR | PURGE_TXABORT);

bOpened = true;
return true;
}

// 关闭串口
public bool ClosePort()
{
if (hComm == INVALID_HANDLE_VALUE)
{
return false;
}

if (CloseHandle(hComm))
{
hComm = INVALID_HANDLE_VALUE;
bOpened = false;
return true;
}
else
{
return false;
}
}

// 往串口写数据
public bool WritePort(byte[] WriteBytes)
{
if (hComm == INVALID_HANDLE_VALUE)
{
return false;
}

COMSTAT ComStat = new COMSTAT();
int dwErrorFlags = 0;

ClearCommError(hComm, ref dwErrorFlags, ref ComStat);
if (dwErrorFlags != 0)
PurgeComm(hComm, PURGE_TXCLEAR | PURGE_TXABORT);

OVERLAPPED ovlCommPort = new OVERLAPPED();
int BytesWritten = 0;
return WriteFile(hComm, WriteBytes, WriteBytes.Length, ref BytesWritten, ref ovlCommPort);
}

// 从串口读数据
public bool ReadPort(int NumBytes, ref byte[] commRead)
{
if (hComm == INVALID_HANDLE_VALUE)
{
return false;
}

COMSTAT ComStat = new COMSTAT();
int dwErrorFlags = 0;

ClearCommError(hComm, ref dwErrorFlags, ref ComStat);
if (dwErrorFlags != 0)
PurgeComm(hComm, PURGE_RXCLEAR | PURGE_RXABORT);

if (ComStat.cbInQue > 0)
{
OVERLAPPED ovlCommPort = new OVERLAPPED();
int BytesRead = 0;
return ReadFile(hComm, commRead, NumBytes, ref BytesRead, ref ovlCommPort);
}
else
{
return false;
}
}
}
}