C# 用API操作读写串口.docx
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C#用API操作读写串口
usingSystem;
usingSystem.Runtime.InteropServices;
usingSystem.Threading;
usingSystem.Windows.Forms;
namespaceDataGate//
{
publicclassComBase
{
publicComBase（stringPortNum,intBaudRate,byteByteSize,byteParity,byteStopBits,intReadTimeout）
{
this.PortNum=PortNum;
this.BaudRate=BaudRate;
this.ByteSize=ByteSize;
this.Parity=Parity;
this.StopBits=StopBits;
this.ReadTimeout=ReadTimeout;
this.Opened=false;
this.m_ovWrite.hEvent=CreateEvent（0,true,false,0）;
this.m_ovWrite.Internal=0;
this.m_ovWrite.InternalHigh=0;
this.m_ovWrite.Offset=0;
this.m_ovWrite.OffsetHigh=0;
this.m_ovRead.hEvent=CreateEvent（0,true,false,0）;
this.m_ovRead.Internal=0;
this.m_ovRead.InternalHigh=0;
this.m_ovRead.Offset=0;
this.m_ovRead.OffsetHigh=0;
}
publicstringPortNum;//COM1COM2COM3COM4
publicintBaudRate;//1200,2400,4800,9600
publicbyteByteSize;//8bits
publicbyteParity;//0-4=no,odd,even,mark,space
publicbyteStopBits;//0,1,2=1,1.5,2
publicintReadTimeout;//10
//commportwin32filehandle
privateinthComm=-1;
publicboolOpened=false;
OVERLAPPEDm_ovWrite=newOVERLAPPED（）;
OVERLAPPEDm_ovRead=newOVERLAPPED（）;
//win32apiconstants
privateconstuintGENERIC_READ=0x80000000;
privateconstuintGENERIC_WRITE=0x40000000;
privateconstintOPEN_EXISTING=3;
privateconstintINVALID_HANDLE_VALUE=-1;
[StructLayout（LayoutKind.Sequential）]
/*
privatestructDCB貌似设置有错误位域没设置对
{
//takenfromcstructinplatformsdk
publicintDCBlength;//sizeof（DCB）
publicintBaudRate;//currentbaudrate
publicintfBinary;//binarymode,noEOFcheck
publicintfParity;//enableparitychecking
publicintfOutxCtsFlow;//CTSoutputflowcontrol
publicintfOutxDsrFlow;//DSRoutputflowcontrol
publicintfDtrControl;//DTRflowcontroltype
publicintfDsrSensitivity;//DSRsensitivity
publicintfTXContinueOnXoff;//XOFFcontinuesTx
publicintfOutX;//XON/XOFFoutflowcontrol
publicintfInX;//XON/XOFFinflowcontrol
publicintfErrorChar;//enableerrorreplacement
publicintfNull;//enablenullstripping
publicintfRtsControl;//RTSflowcontrol
publicintfAbortOnError;//abortonerror
publicintfDummy2;//reserved
publicushortwReserved;//notcurrentlyused
publicushortXonLim;//transmitXONthreshold
publicushortXoffLim;//transmitXOFFthreshold
publicbyteByteSize;//numberofbits/byte,4-8
publicbyteParity;//0-4=no,odd,even,mark,space
publicbyteStopBits;//0,1,2=1,1.5,2
publiccharXonChar;//TxandRxXONcharacter
publiccharXoffChar;//TxandRxXOFFcharacter
publiccharErrorChar;//errorreplacementcharacter
publiccharEofChar;//endofinputcharacter
publiccharEvtChar;//receivedeventcharacter
publicushortwReserved1;//reserved;donotuse
}
*/
privatestructDCB
{
//takenfromcstructinplatformsdk
publicintDCBlength;//sizeof（DCB）
publicintBaudRate;//currentbaudrate
publicintxData;//x值一个32位
publicushortwReserved;//notcurrentlyused
publicushortXonLim;//transmitXONthreshold
publicushortXoffLim;//transmitXOFFthreshold
publicbyteByteSize;//numberofbits/byte,4-8
publicbyteParity;//0-4=no,odd,even,mark,space
publicbyteStopBits;//0,1,2=1,1.5,2
publiccharXonChar;//TxandRxXONcharacter
publiccharXoffChar;//TxandRxXOFFcharacter
publiccharErrorChar;//errorreplacementcharacter
publiccharEofChar;//endofinputcharacter
publiccharEvtChar;//receivedeventcharacter
publicushortwReserved1;//reserved;donotuse
}
[StructLayout（LayoutKind.Sequential）]
privatestructCOMMTIMEOUTS
{
publicintReadIntervalTimeout;
publicintReadTotalTimeoutMultiplier;
publicintReadTotalTimeoutConstant;
publicintWriteTotalTimeoutMultiplier;
publicintWriteTotalTimeoutConstant;
}
[StructLayout（LayoutKind.Sequential）]
privatestructOVERLAPPED
{
publicintInternal;
publicintInternalHigh;
publicintOffset;
publicintOffsetHigh;
publicinthEvent;
}
[DllImport（"kernel32.dll"）]
privatestaticexternintCreateFile（
stringlpFileName,//filename
uintdwDesiredAccess,//accessmode
intdwShareMode,//sharemode
intlpSecurityAttributes,//SD
intdwCreationDisposition,//howtocreate
intdwFlagsAndAttributes,//fileattributes
inthTemplateFile//handletotemplatefile
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolGetCommTimeouts（
inthFile,//handletocommdevice
refCOMMTIMEOUTSlpCommTimeouts//time-outvalues
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolGetCommState（
inthFile,//handletocommunicationsdevice
refDCBlpDCB//device-controlblock
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolSetCommState（
inthFile,//handletocommunicationsdevice
refDCBlpDCB//device-controlblock
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolSetCommTimeouts（
inthFile,//handletocommdevice
refCOMMTIMEOUTSlpCommTimeouts//time-outvalues
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolReadFile（
inthFile,//handletofile
byte[]lpBuffer,//databuffer
intnNumberOfBytesToRead,//numberofbytestoread
refintlpNumberOfBytesRead,//numberofbytesread
refOVERLAPPEDlpOverlapped//overlappedbuffer
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolWriteFile（
inthFile,//handletofile
byte[]lpBuffer,//databuffer
intnNumberOfBytesToWrite,//numberofbytestowrite
refintlpNumberOfBytesWritten,//numberofbyteswritten
refOVERLAPPEDlpOverlapped//overlappedbuffer
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolCloseHandle（
inthObject//handletoobject
）;
[DllImport（"kernel32.dll"）]
privatestaticexternintGetLastError（
）;
[DllImport（"kernel32.dll"）]
privatestaticexternintWaitForSingleObject（
inthHandle,
intdwMilliseconds
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolGetOverlappedResult（
inthFile,//handletofile,pipe,orcommdevice
refOVERLAPPEDlpOverlapped,//pointertooverlappedstructure
refintlpNumberOfBytesTransferred,//pointertoactualbytescount
boolbWait//waitflag
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolPurgeComm（
inthFile,//handletocommunicationsresource
intdwFlags//actiontoperform
）;
[DllImport（"kernel32.dll"）]
privatestaticexternboolSetupComm（
inthFile,//handletocommunicationsdevice
intdwInQueue,//sizeofinputbuffer
intdwOutQueue//sizeofoutputbuffer
）;
[DllImport（"kernel32.dll"）]
privatestaticexternintCreateEvent（
intlpSECURITY_ATTRIBUTES,//传递个NULL就是0
//pointertosecurityattributes
boolbManualReset,//flagformanual-resetevent
boolbInitialState,//flagforinitialstate
intlpName//pointertoevent-objectname
）;
publicvoidOpen（）
{
DCBdcbCommPort=newDCB（）;
COMMTIMEOUTSctoCommPort=newCOMMTIMEOUTS（）;
//OPENTHECOMMPORT.
intFILE_FLAG_OVERLAPPED=0x40000000;
hComm=CreateFile（PortNum,GENERIC_READ|GENERIC_WRITE,0,0,OPEN_EXISTING,FILE_FLAG_OVERLAPPED,0）;
//IFTHEPORTCANNOTBEOPENED,BAILOUT.
if（hComm==INVALID_HANDLE_VALUE）
{
throw（newApplicationException（this.PortNum+"串口打开失败"））;
}
//SETBAUDRATE,PARITY,WORDSIZE,ANDSTOPBITS.
//THEREAREOTHERWAYSOFDOINGSETTINGTHESEBUTTHISISTHEEASIEST.
//IFYOUWANTTOLATERADDCODEFOROTHERBAUDRATES,REMEMBER
//THATTHEARGUMENTFORBuildCommDCBMUSTBEAPOINTERTOASTRING.
//ALSONOTETHATBuildCommDCB（）DEFAULTSTONOHANDSHAKING.
dcbCommPort.DCBlength=Marshal.SizeOf（dcbCommPort）;
GetCommState（hComm,refdcbCommPort）;
dcbCommPort.BaudRate=BaudRate;
dcbCommPort.Parity=Parity;
dcbCommPort.ByteSize=ByteSize;
dcbCommPort.StopBits=StopBits;
dcbCommPort.wReserved1=0;
SetCommState（hComm,refdcbCommPort）;
boolret=SetupComm（hComm,200,200）;//十分重要不然会写进去字节过多发不出去那么多
if（!
ret）
{
MessageBox.Show（"设置缓冲区失败"）;
}
//SETTHECOMMTIMEOUTS.
GetCommTimeouts（hComm,refctoCommPort）;
ctoCommPort.ReadIntervalTimeout=10*9600/this.BaudRate+100;//9600:
110
ctoCommPort.ReadTotalTimeoutConstant=ReadTimeout;
ctoCommPort.ReadTotalTimeoutMultiplier=10*9600/this.BaudRate;
ctoCommPort.WriteTotalTimeoutMultiplier=0;
ctoCommPort.WriteTotalTimeoutConstant=2*9600/this.BaudRate;
SetCommTimeouts（hComm,refctoCommPort）;
Opened=true;
this.ClearInOut（）;
}
publicvoidClose（）
{
if（hComm!
=INVALID_HANDLE_VALUE）
{
CloseHandle（hComm）;
Opened=false;
CloseHandle（m_ovRead.hEvent）;
CloseHandle（m_ovWrite.hEvent）;
}
}
publicvoidClearInOut（）
{
if（this.hComm==INVALID_HANDLE_VALUE）
return;
intPURGE_TXABORT=0x0001;//Killthepending/currentwritestothecommport.
intPURGE_RXABORT=0x0002;//Killthepending/currentreadstothecommport.
intPURGE_TXCLEAR=0x0004;//Killthetransmitqueueifthere.
intPURGE_RXCLEAR=0x0008;//Killthetypeaheadbufferifthere.
PurgeComm（hComm,PURGE_TXABORT|PURGE_RXABORT|PURGE_TXCLEAR|PURGE_RXCLEAR）;
}
publicbyte[]Read（intNumBytes）
{
byte[]BufBytes;
byte[]OutBytes=null;
BufBytes=newbyte[NumBytes];
intERROR_IO_PENDING=997;
if（hComm!
=INVALID_HANDLE_VALUE）
{
intBytesRead=0;
boolbOK=ReadFile（hComm,BufBytes,NumBytes,refBytesRead,refm_ovRead）;
if（bOK==true）
{
OutBytes=newbyte[BytesRead];
Array.Copy（BufBytes,OutBytes,BytesRead）;
}
else
{
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