qDebug重定向到日志文件

直接上代码：

#include "mainwindow.h"

#include 
#include 
#include 
#include 

void log_message_handler(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{
    static QMutex mutex;
    mutex.lock();
    QFile f("Server.log");
    f.open(QFile::OpenModeFlag::Append | QFile::OpenModeFlag::Text);
    if (!f.isOpen()) {
        mutex.unlock();
        return;
    }
    QTime t = QTime::currentTime();
    QString timestr = t.toString("hh::mm::ss");
    QByteArray localMsg = msg.toLocal8Bit();
    char log_buffer[4096] = {0};
    switch (type) {
    case QtDebugMsg:
        sprintf(log_buffer, "[%s]Debug: %s \t( %s,%u)\n", timestr.toStdString().c_str(), localMsg.constData(), /*context.file,*/ context.function, context.line);
        break;
    case QtInfoMsg:
        sprintf(log_buffer, "[%s]Info: %s \t(%s,%u)\n", timestr.toStdString().c_str(), localMsg.constData(), /*context.file,*/ context.function, context.line);
        break;
    case QtWarningMsg:
        sprintf(log_buffer, "[%s]Warning: %s \t(%s,%u)\n", timestr.toStdString().c_str(), localMsg.constData(), /*context.file,*/ context.function, context.line);
        break;
    case QtCriticalMsg:
        sprintf(log_buffer, "[%s]Critical: %s \t(%s,%u)\n", timestr.toStdString().c_str(), localMsg.constData(), /*context.file,*/ context.function, context.line);
        break;
    case QtFatalMsg:
        sprintf(log_buffer, "[%s]Fatal: %s \t(%s,%u)\n", timestr.toStdString().c_str(), localMsg.constData(), /*context.file, */ context.function, context.line);
    }
    f.write(log_buffer);
    f.flush();
    f.close();
    mutex.unlock();
    if (type == QtFatalMsg)
        abort();
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    qInstallMessageHandler(log_message_handler);
    QTextCodec::setCodecForLocale(QTextCodec::codecForName("GBK"));
    MainWindow w;
    w.show();
    return a.exec();
}