错误 C2664: 'int wsprintfW(LPWSTR,LPCWSTR,...)': 无法将参数 1 从 'char [15]' 转换为 'LPWSTR'

Question

我正在关注本教程以在 Windows (http://www.codeguru.com/cpp/i-n/network/serialcommunications/article.php/c2503/CSerial--A-C-Class-for-Serial-Communications.htm) 中进行串行通信。我收到以下错误，代码已经过时了，所以我不确定这是否是版本问题。我正在使用 Visual Studio 2015 在 Windows 10 上运行。

串行.cpp： // Serial.cpp

#include "stdafx.h"

CSerial::CSerial()
{

    memset( &m_OverlappedRead, 0, sizeof( OVERLAPPED ) );
    memset( &m_OverlappedWrite, 0, sizeof( OVERLAPPED ) );
    m_hIDComDev = NULL;
    m_bOpened = FALSE;

}

CSerial::~CSerial()
{

    Close();

}

BOOL CSerial::Open( int nPort, int nBaud )
{

    if( m_bOpened ) return( TRUE );

    char szPort[15];
    char szComParams[50];
    DCB dcb;

    wsprintf(szPort, "COM%d", nPort );
    m_hIDComDev = CreateFile( szPort, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL );
    if( m_hIDComDev == NULL ) return( FALSE );

    memset( &m_OverlappedRead, 0, sizeof( OVERLAPPED ) );
    memset( &m_OverlappedWrite, 0, sizeof( OVERLAPPED ) );

    COMMTIMEOUTS CommTimeOuts;
    CommTimeOuts.ReadIntervalTimeout = 0xFFFFFFFF;
    CommTimeOuts.ReadTotalTimeoutMultiplier = 0;
    CommTimeOuts.ReadTotalTimeoutConstant = 0;
    CommTimeOuts.WriteTotalTimeoutMultiplier = 0;
    CommTimeOuts.WriteTotalTimeoutConstant = 5000;
    SetCommTimeouts( m_hIDComDev, &CommTimeOuts );

    wsprintf( szComParams, "COM%d:%d,n,8,1", nPort, nBaud );

    m_OverlappedRead.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );
    m_OverlappedWrite.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );

    dcb.DCBlength = sizeof( DCB );
    GetCommState( m_hIDComDev, &dcb );
    dcb.BaudRate = nBaud;
    dcb.ByteSize = 8;
    unsigned char ucSet;
    ucSet = (unsigned char) ( ( FC_RTSCTS & FC_DTRDSR ) != 0 );
    ucSet = (unsigned char) ( ( FC_RTSCTS & FC_RTSCTS ) != 0 );
    ucSet = (unsigned char) ( ( FC_RTSCTS & FC_XONXOFF ) != 0 );
    if( !SetCommState( m_hIDComDev, &dcb ) ||
        !SetupComm( m_hIDComDev, 10000, 10000 ) ||
        m_OverlappedRead.hEvent == NULL ||
        m_OverlappedWrite.hEvent == NULL ){
        DWORD dwError = GetLastError();
        if( m_OverlappedRead.hEvent != NULL ) CloseHandle( m_OverlappedRead.hEvent );
        if( m_OverlappedWrite.hEvent != NULL ) CloseHandle( m_OverlappedWrite.hEvent );
        CloseHandle( m_hIDComDev );
        return( FALSE );
        }

    m_bOpened = TRUE;

    return( m_bOpened );

}

BOOL CSerial::Close( void )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( TRUE );

    if( m_OverlappedRead.hEvent != NULL ) CloseHandle( m_OverlappedRead.hEvent );
    if( m_OverlappedWrite.hEvent != NULL ) CloseHandle( m_OverlappedWrite.hEvent );
    CloseHandle( m_hIDComDev );
    m_bOpened = FALSE;
    m_hIDComDev = NULL;

    return( TRUE );

}

BOOL CSerial::WriteCommByte( unsigned char ucByte )
{
    BOOL bWriteStat;
    DWORD dwBytesWritten;

    bWriteStat = WriteFile( m_hIDComDev, (LPSTR) &ucByte, 1, &dwBytesWritten, &m_OverlappedWrite );
    if( !bWriteStat && ( GetLastError() == ERROR_IO_PENDING ) ){
        if( WaitForSingleObject( m_OverlappedWrite.hEvent, 1000 ) ) dwBytesWritten = 0;
        else{
            GetOverlappedResult( m_hIDComDev, &m_OverlappedWrite, &dwBytesWritten, FALSE );
            m_OverlappedWrite.Offset += dwBytesWritten;
            }
        }

    return( TRUE );

}

int CSerial::SendData( const char *buffer, int size )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );

    DWORD dwBytesWritten = 0;
    int i;
    for( i=0; i<size; i++ ){
        WriteCommByte( buffer[i] );
        dwBytesWritten++;
        }

    return( (int) dwBytesWritten );

}

int CSerial::ReadDataWaiting( void )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );

    DWORD dwErrorFlags;
    COMSTAT ComStat;

    ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );

    return( (int) ComStat.cbInQue );

}

int CSerial::ReadData( void *buffer, int limit )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );

    BOOL bReadStatus;
    DWORD dwBytesRead, dwErrorFlags;
    COMSTAT ComStat;

    ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );
    if( !ComStat.cbInQue ) return( 0 );

    dwBytesRead = (DWORD) ComStat.cbInQue;
    if( limit < (int) dwBytesRead ) dwBytesRead = (DWORD) limit;

    bReadStatus = ReadFile( m_hIDComDev, buffer, dwBytesRead, &dwBytesRead, &m_OverlappedRead );
    if( !bReadStatus ){
        if( GetLastError() == ERROR_IO_PENDING ){
            WaitForSingleObject( m_OverlappedRead.hEvent, 2000 );
            return( (int) dwBytesRead );
            }
        return( 0 );
        }

    return( (int) dwBytesRead );

}

错误：

1>c:\..\consoleapplication2\serial.cpp(31): error C2664: 'int wsprintfW(LPWSTR,LPCWSTR,...)': cannot convert argument 1 from 'char [15]' to 'LPWSTR'
1>c:\..\consoleapplication2\serial.cpp(31): note: Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
1>c:\..\consoleapplication2\serial.cpp(32): error C2664: 'HANDLE CreateFileW(LPCWSTR,DWORD,DWORD,LPSECURITY_ATTRIBUTES,DWORD,DWORD,HANDLE)': cannot convert argument 1 from 'char [15]' to 'LPCWSTR'
1>c:\..\consoleapplication2\serial.cpp(32): note: Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
1>c:\..\consoleapplication2\serial.cpp(46): error C2664: 'int wsprintfW(LPWSTR,LPCWSTR,...)': cannot convert argument 1 from 'char [50]' to 'LPWSTR'
1>c:\..\consoleapplication2\serial.cpp(46): note: Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

Answer 1

您的错误信息：

error C2664: 'HANDLE CreateFileW(LPCWS
                               ^ ~~~~

表示您使用 UNICODE 构建（W 表示 CreateFile 宏是使用 CreateFileW 函数定义的），因此您应该在此处（以及在下一个 wsprintf 中）使用宽文本：

 wsprintf(szPort, L"COM%d", nPort );
                  ^ ~~~~~ !

和 wchar_t 数组：

wchar_t szPort[15]; // or under winapi you would use WCHAR
wchar_t szComParams[50];