[C++知识库]QT---按级别输出详细Log信息qInstallMessageHandler

1. 自定义一个消息输出函数

QTextStream *messageStream = NULL;
QMutex msgOutputProtection;

void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{
? ? msgOutputProtection.lock();

? ? switch (type)
? ? {
? ? ? ? case QtDebugMsg:
? ? ? ? ? ? (*messageStream) << "[qDebug ? ?" << ?QDateTime::currentDateTime().toString("dd.MM.yy hh:mm:ss") << "] - " << msg << " ? ? (File: " << context.file << " Line: " << context.line << " Function: " << context.function << ")\n";
? ? ? ? ? ? break;
? ? ? ? case QtWarningMsg:
? ? ? ? ? ? (*messageStream) << "[qWarning ?" << QDateTime::currentDateTime().toString("dd.MM.yy hh:mm:ss") << "] - " << msg << " ? ? (File: " << context.file << " Line: " << context.line << " Function: " << context.function << ")\n";
? ? ? ? ? ? break;
? ? ? ? case QtCriticalMsg:
? ? ? ? ? ? (*messageStream) << "[qCritical " << QDateTime::currentDateTime().toString("dd.MM.yy hh:mm:ss") << "] - " << msg << " ? ? (File: " << context.file << " Line: " << context.line << " Function: " << context.function << ")\n";
? ? ? ? ? ? break;
? ? ? ? case QtFatalMsg:
? ? ? ? ? ? (*messageStream) << "[qFatal ? ?" << QDateTime::currentDateTime().toString("dd.MM.yy hh:mm:ss") << "] - " << msg << " ? ? (File: " << context.file << " Line: " << context.line << " Function: " << context.function << ")\n";
? ? ? ? ? ? abort();
? ? }

? ? messageStream->flush();
? ? msgOutputProtection.unlock();
}

? ?2. 用qInstallMessageHandle挂载

    QFile logfile;

    if (args.contains("log", Qt::CaseInsensitive))

    {

        logfile.setFileName("testlog.txt");

        logfile.open(QIODevice::WriteOnly | QIODevice::Append | QIODevice::Text);

        messageStream = new QTextStream(&logfile);

        //uncomment that line if you want to print all debug-information (qDebug, qWarning...) to file testlog.txt

        qInstallMessageHandler(myMessageOutput);

        //first lines in log file

        logfile.write("------------------------------------------------------------------------------------------\n");

        logfile.write(QString(QDateTime::currentDateTime().toString("dd.MM.yy hh:mm:ss") + " Starting wdmv... \n").toLatin1().constData());

        logfile.write("------------------------------------------------------------------------------------------\n");

    }