Qt实现简单的qDebug输出到日志文件

#include "widget.h" #include <QApplication> #include <QMutex> #include <QIODevice> #include <QDateTime> #include <QDebug> #include <QFile> #include <QDir> #include <QCoreApplication> void outputMessage(QtMsgType type, 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); QString filePath = QApplication::applicationDirPath(); filePath += ("/log.txt"); QFile file(filePath); 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 a(argc, argv); qInstallMessageHandler(outputMessage); //注册MessageHandler //打印日志到文件中 qDebug("\r\nProgram start!"); qDebug("This is a debug message"); qWarning("This is a warning message"); qCritical("This is a critical message"); qDebug()<<"123"; qDebug()<<"456"; Widget w; w.show(); return a.exec(); }