main.cpp

#include <QDebug>

#include <QFile>

#include <QMutex>?? //文件鎖

?

void MyMessageHandler(QtMsgType type,const QMessageLogContext &context,const QString &msg)

{

??? //使用一個文件鎖，當(dāng)在寫文件的時候，要等寫完之后才能繼續(xù)執(zhí)行

??? static QMutex mutex;

??? mutex.lock();

?

??? QString strContext;

??? //在QMessageLogContext中保存的有文件名，文件行號，方法等信息

??? strContext.sprintf("%s %d %s:\r\n\t",context.file,context.line,context.function);

?

??? QString output = strContext + msg + "\r\n";

?

??? if(type == QtDebugMsg)

??? {

??????? QFile file("debug.log");

??????? file.open(QFile::WriteOnly | QFile::Append);

??????? file.write(output.toUtf8());

??????? file.close();

??? }

??? if(type == QtWarningMsg)

??? {

??????? QFile file("warning.log");

??????? file.open(QFile::WriteOnly|QFile::Append);

??? ????file.write(output.toUtf8());

??????? file.close();

??? }

??? if(type == QtCriticalMsg)

??? {

??????? QFile file("critical.log");

??????? file.open(QFile::WriteOnly | QFile::Append);

??????? file.write(output.toUtf8());

??????? file.close();

??? }

??? if(type == QtFatalMsg)

??? {

??????? QFile file("fatal.log");

??????? file.open(QFile::WriteOnly | QFile::Append);

??????? file.write(output.toUtf8());

??????? file.close();

??? }

?

??? printf("%s",output.toUtf8().data());

??? mutex.unlock();

}

?

int main()

{

??? //To suppress the output at runtime, install your own message

??? //handler with qInstallMessageHandler().

??? qInstallMessageHandler(MyMessageHandler);

??? qDebug() << "output debug";

??? qDebug("%s,%d","outputdebug",1);

?

??? qWarning() << "warning";

??? qCritical() << "cridical";

??? //可以放開下面的一句，然后發(fā)現(xiàn)目錄也有相應(yīng)的fatal.log文件

??? //qFatal("fatal info");

}

運(yùn)行結(jié)果：

輸入目錄（E:\QT\build-T33Debug-Desktop_Qt_5_3_MinGW_32bit-Debug）的文件如下：