#include "widget.h"
#include <QApplication>
#include <QtDebug>
#include <QMutex>
#include <QDateTime>
#include <QFile>

void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{
    // 加锁
    static QMutex mutex;
    mutex.lock();
    
    QByteArray localMsg = msg.toLocal8Bit();
    
    QString strMsg("");
    switch(type)
    {
    case QtDebugMsg:
        strMsg = QString("Debug:");
        break;
    case QtWarningMsg:
        strMsg = QString("Warning:");
        break;
    case QtCriticalMsg:
        strMsg = QString("Critical:");
        break;
    case QtFatalMsg:
        strMsg = QString("Fatal:");
        break;
    default: break ;
    }
    
    // 设置输出信息格式
    QString strDateTime = QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss ddd");
    QString strMessage = QString("Message:%1 File:%2  Line:%3  Function:%4  DateTime:%5")
            .arg(localMsg.constData())
            .arg(context.file)
            .arg(context.line)
            .arg(context.function)
            .arg(strDateTime);
    
    // 输出信息至文件中（读写、追加形式）
    QFile file("log.txt");
    file.open(QIODevice::ReadWrite | QIODevice::Append);
    QTextStream stream(&file);
    stream << strMessage << "\r\n";
    file.flush();
    file.close();
    
    // 解锁
    mutex.unlock();
}


int main(int argc, char *argv[])
{
    // 安装消息处理程序
    qInstallMessageHandler(myMessageOutput);
    
    QApplication a(argc, argv);
    
    qDebug("This is a debug message.");
    qWarning("This is a warning message.");
    qCritical("This is a critical message.");
    qFatal("This is a fatal message.");
    
    Widget w ;
    w.show();
    
    return a.exec();
}

#include <QApplication>
#include <stdio.h>
#include <stdlib.h>

// 自定义消息处理程序
void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{
    QByteArray localMsg = msg.toLocal8Bit();
    switch (type) {
    case QtDebugMsg:
        fprintf(stderr, "Debug: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function);
        break;
    case QtInfoMsg:
        fprintf(stderr, "Info: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function);
        break;
    case QtWarningMsg:
        fprintf(stderr, "Warning: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function);
        break;
    case QtCriticalMsg:
        fprintf(stderr, "Critical: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function);
        break;
    case QtFatalMsg:
        fprintf(stderr, "Fatal: %s (%s:%u, %s)\n", localMsg.constData(), context.file, context.line, context.function);
        abort();
    }
}

int main(int argc, char **argv)
{
    QApplication app(argc, argv);

    // 安装消息处理程序
    qInstallMessageHandler(myMessageOutput);

    // 打印信息
    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();
}