日志

使用qt提供的类 写日志到log.txt文件中。

//以下代码使用qt4的类。能够写入日志到log.txt文件中。亲测。

#include "test_log.h"

#include <QtGui/QApplication>

#include <QMutex>

#include <QtMsgHandler>

#include <QDebug>

#include <QDateTime>

#include <QFile>

void outputMessage(QtMsgType type, const char * msg/*const QMessageLogContext &context,*/ /*const QString &msg*/)

{

static QMutex mutex;

mutex.lock();

QString text;

switch(type)

{

case QtDebugMsg:

text = QString("Debug:");

break;

case QtWarningMsg:

text = QString("Warning:");

break;

case QtCriticalMsg:

text = QString("Critical:");

break;

case QtFatalMsg:

text = QString("Fatal:");

}

QString context_info = QString("File:(%1) Line:(%2)");;//.arg(QString(context.file)).arg(context.line);

QString current_date_time = QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss ddd");

QString current_date = QString("(%1)").arg(current_date_time);

QString message = QString("%1 %2 %3 %4").arg(text).arg(context_info).arg(msg).arg(current_date);

QFile file("log.txt");

file.open(QIODevice::WriteOnly | QIODevice::Append);

QTextStream text_stream(&file);

text_stream << message << "\r\n";

file.flush();

file.close();

mutex.unlock();

}

int main(int argc, char *argv[])

{

QApplication app(argc, argv);

//注册MessageHandler

qInstallMsgHandler(outputMessage);

//打印日志到文件中

qDebug("This is a debug message");

qWarning("This is a warning message");

qCritical("This is a critical message");

qFatal("This is a fatal message");

return app.exec();

}