在 Visual Studio 中锁定 Output 到 Output Window

Question

My application sends debug data to the Output Window in Visual Studio using the TRACE macro. Some of these output strings are built using several calls to the TRACE macro, as is shown in the following snippet of code:

BYTE i, len;

len = pMsg[APP_LEN_OFFSET] + sizeof(appPktHead_t) - APP_MSG_CODE_LEN;

TRACE(_T("%s: "), fnName);
TRACE(GetCmdIdStr( pMsg[APP_MSG_CODE_OFFSET] ));
TRACE(_T(" 0x"));

for ( i = 0; i < len; i++ )
{
    TRACE(_T("%.2X "), pMsg[i]);
}

TRACE(_T("\r\n"));

How can I either lock the output to the Output Window for the duration of this function, or send the entire string in a single call to TRACE ? Thanks.

Answer 1

I don't believe there is a way to lock the output window in Visual Studio. I think the easiest way to do this is to build up the entire message into a std::stringstream or wchar_t[] object and then output that single value to the TRACE macro

Been awhile since I used stringstream so there are likely a few errors here but the following should get you on the right track

std::stringstream stream;
stream << fnName << ": ";
stream << GetCmdIdStr( pMsg[APP_MSG_CODE_OFFSET] );
stream << " 0x";
for ( i = 0; i < len; i++ )
{
    stream << pMsg[i] << " ";
}

stream << "\r\n";
TRACE(stream.str().c_str());

Answer 2

Build a single string, before using the TRACE macro.

byMsgLen = pMsg[DEV_LEN_OFFSET] + sizeof(devPktHead_t) + sizeof(devPktTail_t);
cmd = pMsg[DEV_CMD_MSB_OFFSET];
cmd <<= 8;
cmd |= pMsg[DEV_CMD_LSB_OFFSET];
pCmdIdStr = GetCmdIdStr( cmd );
iPreOffset = ::wcsnlen_s(fnName, 128)       // function name
    + 2                                     // ": "
    + ::wcsnlen_s(pCmdIdStr, 128)           // command ID string
    + 3;                                    // " 0x"
iPostOffset = iPreOffset + byMsgLen * 3;    // "%.2X " (formatted: 2 hex-nibble bytes and space)
iStrLen = iPostOffset + 3;                  // "\r\n\0"
pBuf = (wchar_t *)malloc( iStrLen * sizeof(wchar_t) );

::swprintf_s( pBuf, iStrLen, _T("%s: %s 0x"), fnName, pCmdIdStr);

for ( i = iPreOffset; i < iPostOffset; i += 3 )
{
    ::swprintf_s( &(pBuf[i]), 4, _T("%.2X "), pMsg[j++] );
}

::swprintf_s( &(pBuf[i]), 3, _T("\r\n") );

TRACE( pBuf );

::free( pBuf );