Qt利用qInstallMessageHandler输出日志QtLogOut

 1 QT       += core gui
 2 
 3 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 4 
 5 CONFIG += c++11
 6 
 7 # The following define makes your compiler emit warnings if you use
 8 # any Qt feature that has been marked deprecated (the exact warnings
 9 # depend on your compiler). Please consult the documentation of the
10 # deprecated API in order to know how to port your code away from it.
11 DEFINES += QT_DEPRECATED_WARNINGS
12 
13 # You can also make your code fail to compile if it uses deprecated APIs.
14 # In order to do so, uncomment the following line.
15 # You can also select to disable deprecated APIs only up to a certain version of Qt.
16 #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
17 
18 SOURCES += \
19     main.cpp \
20     mainwindow.cpp
21 
22 HEADERS += \
23     mainwindow.h
24 
25 FORMS += \
26     mainwindow.ui
27 
28 # Default rules for deployment.
29 qnx: target.path = /tmp/$${TARGET}/bin
30 else: unix:!android: target.path = /opt/$${TARGET}/bin
31 !isEmpty(target.path): INSTALLS += target

 1 #include "mainwindow.h"
 2 
 3 #include <QApplication>
 4 #include <QMutex>
 5 #include <QFile>
 6 #include <QTextStream>
 7 #include <QDateTime>
 8 
 9 void outputMessage(QtMsgType type, const QMessageLogContext &context, const QString &msg)
10 {
11     static QMutex mutex;
12     mutex.lock();
13 
14     QString text;
15     switch(type)
16     {
17     case QtDebugMsg:
18         text = QString("Debug:");
19         break;
20 
21     case QtWarningMsg:
22         text = QString("Warning:");
23         break;
24 
25     case QtCriticalMsg:
26         text = QString("Critical:");
27         break;
28 
29     case QtFatalMsg:
30         text = QString("Fatal:");
31     }
32 
33     QString context_info = QString("File:(%1) Line:(%2)").arg(QString(context.file)).arg(context.line);
34     QString current_date_time = QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss ddd");
35     QString current_date = QString("(%1)").arg(current_date_time);
36     QString message = QString("%1 %2 %3 %4").arg(text).arg(context_info).arg(msg).arg(current_date);
37 
38     QFile file("d:/log.txt");
39     file.open(QIODevice::WriteOnly | QIODevice::Append);
40     QTextStream text_stream(&file);
41     text_stream << message << "\r\n";
42     file.flush();
43     file.close();
44 
45     mutex.unlock();
46 }
47 
48 int main(int argc, char *argv[])
49 {
50     QApplication a(argc, argv);
51 
52     //注册MessageHandler
53     qInstallMessageHandler(outputMessage);
54 
55     //打印日志到文件中
56     qDebug("This is a debug message");
57     qWarning("This is a warning message");
58     qCritical("This is a critical message");
59     qFatal("This is a fatal message!");
60 
61     MainWindow w;
62     w.show();
63     return a.exec();
64 }

 1 #ifndef MAINWINDOW_H
 2 #define MAINWINDOW_H
 3 
 4 #include <QMainWindow>
 5 
 6 QT_BEGIN_NAMESPACE
 7 namespace Ui { class MainWindow; }
 8 QT_END_NAMESPACE
 9 
10 class MainWindow : public QMainWindow
11 {
12     Q_OBJECT
13 
14 public:
15     MainWindow(QWidget *parent = nullptr);
16     ~MainWindow();
17 
18 private:
19     Ui::MainWindow *ui;
20 };
21 #endif // MAINWINDOW_H

 1 #include "mainwindow.h"
 2 #include "ui_mainwindow.h"
 3 
 4 MainWindow::MainWindow(QWidget *parent)
 5     : QMainWindow(parent)
 6     , ui(new Ui::MainWindow)
 7 {
 8     ui->setupUi(this);
 9 }
10 
11 MainWindow::~MainWindow()
12 {
13     delete ui;
14 }