坚决收藏一下

PC机串口的操做使用mscomm32.ocx 控件，会带来很多问题。在WIN7-64,win8.1,win10下，几乎无法运行，用API直接调用WIN的底层库，兼容性，程序代码可读性非常好：
打开COM1
HANDLE hCom = CreateFile(TEXT("COM1"), GENERIC_READ|GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if( hCom==INVALID_HANDLE_VALUE ) return false;

设置 波特率、奇偶校验、停止位 等等
DCB CommDCB;
GetCommState( hCom, &CommDCB );
CommDCB.BaudRate = BaudRate;
CommDCB.Parity = EVENPARITY;
CommDCB.StopBits = ONESTOPBIT;
CommDCB.ByteSize = 8;
CommDCB.fBinary = 1;
CommDCB.fParity = 1;
CommDCB.fOutxCtsFlow = 0;
CommDCB.fOutxDsrFlow = 0;
CommDCB.fDtrControl = 0;
CommDCB.fDsrSensitivity = 0;
CommDCB.fTXContinueOnXoff = 0;
CommDCB.fOutX = 0;
CommDCB.fInX = 0;
CommDCB.fErrorChar = 0;
CommDCB.fNull = 0;
CommDCB.fRtsControl = RTS_CONTROL_TOGGLE;
CommDCB.fAbortOnError = 0;
SetCommState( hCom, &CommDCB );

设置缓冲大小
SetupComm( hCom, 100, 100 );

设置超时时间
COMMTIMEOUTS CommTimeouts;
GetCommTimeouts( hCom, &CommTimeouts );
CommTimeouts.ReadIntervalTimeout = MAXDWORD;
CommTimeouts.ReadTotalTimeoutMultiplier = 0;
CommTimeouts.ReadTotalTimeoutConstant = 0;
SetCommTimeouts( hCom, &CommTimeouts );

/////////////// 这期间就是对COM进行读写了 ///////////////
COMSTAT ComStat; ClearCommError(hCom,&Errors,&ComStat); 后 ComStat.cbInQue 保存着一个数值，指明还有多少字节已经获得但没有用ReadFile取走。
读用 ReadFile，写用 WriteFile。
/////////////////////////////////////////////////////////

关闭COM
CloseHandle( hCom );

上传一个C代码的程序，是2005用过的。

本帖最后由 mon51 于 2017-6-17 13:04 编辑

gmyu 发表于 2017-6-17 12:45
你有调用api的VB程序么？好久没搞，发现以前国外的一个程序在office2010 win7 64下面不能用了。 前段时间 ...

'****************************************************************************************************************************************
Public Declare Function OpenComm Lib "User" (ByVal IpComName As String, ByVal wInQueue As Integer, ByVal wOutQueue As Integer) As Integer

Public Declare Function SetCommState Lib "User" (IpDCB As DCB) As Integer

Public Declare Function ReadComm Lib "User" (ByVal nCid As Integer, ByVal IpBuf As String, ByVal nSize As Integer) As Integer

Public Declare Function WriteComm Lib "User" (ByVal nCid As Integer, ByVal IpBuf As String, ByVal nSize As Integer) As Integer

Public Declare Function Closecomm Lib "User" (ByVal nCid As Integer) As Integer

Public Declare Function BuildCommDCB Lib "User" (ByVal IpDef As String, IpDCB As DCB) As Integer

Public Declare Function GetCommError Lib "User" (ByVal nCid As Integer, IpStat As COMSTAT) As Integer
'****************************************************************************************************************************************

Type DCB

    Id As String
   
    BaudRate As Integer
   
    ByteSize As String
   
    Parity As String
   
    StopBits As String
   
    RlsTimeout As Integer
   
    CtsTimeout As Integer
   
    DsrTimeout As Integer
   
    Bits1 As String
   
    Bits2 As String
   
    XonChar As String
   
    XoffChar As String
   
    XonLim As Integer
   
    XoffLim As Integer
   
    PeChar As String
   
    EofChar As String
   
    EvtChar As String
   
    TxDelay As Integer

End Type

Type COMSTAT

    Bits As String
   
    cbInQue As Integer
   
    cbOutQue As Integer

End Type

'*************************************************************************************

Public IpDCB As DCB

Public nCid As Integer


VB用得少，这个是从来软件中COPY出来得头文件。可以用。

'*************************************************************************************
'初始化串口返回=-1 无效！
Public Function Init_Comm(com_id As String) As Integer
    nCid = OpenComm(com_id, 512, 512) '′打开COM2 设置接收,发送缓冲区为512 字节
   
    If nCid < 0 Then
        Init_Comm = -1 '′处理错误
    Else
        Init_Comm = cCid
    End If
   
End Function
'*********************************************************************************
Public Function Build_Comm(com_Info As String) As Integer
    Dim comset As String
    Dim err As Integer
   
    err = 0
    comset = com_Info + "  ,n ,8 ,1" '"COM2 :9600 ,n ,8 ,1"
    If (BuildCommDCB(comset, LpDCB)) Then err = -1 ' 无法创建
   
    LpDCB.Id = Chr(nCid)
   
    If (SetCommState(LpDCB)) Then err = -2 ' 无法创建′设置串口状态
    Build_Comm = err
   
End Function
'**************************************************************************
'发送数据
Public Function Send_Data_Out_Comm(p As String, cnt As Integer) As Integer

    Dim nsend As Integer, x As Integer
   
    Dim Lpstate As COMSTAT '通信状态块
   
    x = GetCommError(nCid, Lpstate)  '′读取当前串口错误或状态
   
    If Lpstate.cbOutQue < 512 Then  '′送缓冲区有空间否?
   
        nsend = WriteComm(nCid, p, cnt)   '′发送inbuff
   
        If nsend <= 0 Then nsend = -nsend  ' '′忽略错误
  
    End If
   
    Send_Data_Out_Comm = cnt
End Function
'**************************************************************************
'读取数据
Public Function Read_Data_Out_Comm(p() As String) As Integer

    Dim nsend As Integer, x As Integer
   
    Dim Lpstate As COMSTAT '通信状态块
   
        
   
    x = GetCommError(nCid, Lpstate)  '′读取当前串口错误或状态
   
    If Lpstate.cbInQue < 512 Then  '′缓冲区有空间否?
   
        nsend = ReadComm(nCid, p, cnt)   '′发送inbuff
   
        If nsend <= 0 Then nsend = -nsend  ' '′忽略错误
  
    End If
   
    Read_Data_Out_Comm = Lpstate.cbInQue
End Function

'***********************************************************************************
'关闭串口，释放资源
Public Function Close_Comm()
    Dim Nclose As Integer
   
    Nclose = Closecomm(nCid)
   
    nCid = 0
   
End Function