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:
            (*messageStrea