[C++知识库]Qt 自定义日志类

日志类

此类使用qInstallMessageHandler注册一个自定义的消息处理器替换掉默认QtMessageHandler。

通过 qInstallMessageHandler(QtMessageHandler handler)函数注册一个自定义的 MessageHandler，QtMessageHandler 的定义如下：

typedef void (*QtMessageHandler)(QtMsgType, const QMessageLogContext &, const QString &);

可以看到，QtMessageHandler 并不是一个类，而是一个函数指针，函数原型满足?void myMessageHandler(QtMsgType, const QMessageLogContext &, const QString &)的函数都可以作为 QtMessageHandler 参数传递个?qInstallMessageHandler?函数中。

话不多说，上代码。

Wlog.h

#ifndef WLOG_H
#define WLOG_H

//解决中文乱码 源代码编码必须是: UTF-8(BOM)
#if _MSC_VER >= 1600
#pragma execution_character_set("utf-8")
#endif

#include <QObject>
#include <QDebug>
#include <string>

#ifdef _WIN64
#define filename(x) strrchr(x,'\\')?strrchr(x,'\\')+1:x
#else
#define filename(x) strrchr(x,'/')?strrchr(x,'/')+1:x
#endif

#ifdef _WIN64
#define INFO_PRINT qDebug()<<"[INFO]"
#define SUCCESS_PRINT qDebug()<<"[SUCCESS]"
#define ERROR_PRINT qDebug()<<"[ERROR]"
#define FOCUS_PRINT qDebug()<<"[FOCUS]"

#define INFO_PRINT_LINE qDebug()<<"[INFO]"<<(filename(__FILE__))<<__LINE__
#define SUCCESS_PRINT_LINE qDebug()<<"[SUCCESS]"<<(filename(__FILE__))<<__LINE__
#define ERROR_PRINT_LINE qDebug()<<"[ERROR]"<<(filename(__FILE__))<<__LINE__
#define FOCUS_PRINT_LINE qDebug()<<"[FOCUS]"<<(filename(__FILE__))<<__LINE__
#else
#define INFO_PRINT qDebug()<<"\033[0m[INFO] "
#define SUCCESS_PRINT qDebug()<<"\033[1m\033[32m[SUCCESS]"
#define ERROR_PRINT qDebug()<<"\033[1m\033[31m[ERROR]"
#define FOCUS_PRINT qDebug()<<"\033[1m\033[33m[FOCUS]"
#endif

class Wlog : public QObject
{
    Q_OBJECT

public:
    static Wlog* getInstance();

public:
    void init(QString name = QString());
    QString getName();

public:
    static void loggerOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg);
    static void setColor(QString info);

private:
    Wlog(QObject *parent = nullptr);

private:
    QString m_name;
};

#endif // WLOG_H

Wlog.cpp

#include "Wlog.h"
#include <QMutex>
#include <QDateTime>
#include <fstream>
#include <iostream>
#include <QDir>
#ifdef _WIN64
#include <windows.h>
#endif

Wlog* Wlog::getInstance()
{
    static Wlog instance;
    return &instance;
}

Wlog::Wlog(QObject *parent)
    : QObject(parent)
{

}


void Wlog::init(QString name)
{
    m_name = name;
    QDir dir;
    QString dirName = "./log";
    if (!dir.exists(dirName))
    {
        dir.mkpath(dirName);
    }
    qInstallMessageHandler(Wlog::loggerOutput);
}

QString Wlog::getName()
{
    return m_name;
}

void Wlog::loggerOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{
    static QMutex mutex;
    mutex.lock();
#ifdef _WIN64
    setColor(msg);
#endif
    QString result = msg;
    result = result.remove("\033[0m").remove("\033[32m").remove("\033[31m").remove("\033[21m");
    QByteArray localMsg = result.toLocal8Bit();
    QByteArray originMsg = msg.toLocal8Bit();

    QString strMsg("");
    switch (type)
    {
    case QtDebugMsg:
        strMsg = QString("INFO");
        break;
    case QtWarningMsg:
        strMsg = QString("WARN");
        break;
    case QtCriticalMsg:
        strMsg = QString("ERROR");
        break;
    case QtFatalMsg:
        strMsg = QString("ERROR");
        break;
    }

    // 设置输出信息格式;
    QString strDateTime = QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss.zzz");

    // 输出信息至文件中（读写、追加形式）;
    std::ofstream out("log/" + Wlog::getInstance()->getName().toStdString() + "_" + strMsg.toStdString() + "_" + QDateTime::currentDateTime().toString("yyyy-MM-dd").toStdString() + ".txt", std::ios::app);
    out << strDateTime.toStdString() << " " << localMsg.constData() << std::endl;
    out.flush();
    out.close();

    std::cout <<"["<< strDateTime.toStdString() <<"]"<< originMsg.constData() << std::endl;

#ifdef _WIN64
    //恢复颜色
    setColor("");
#endif
    // 解锁;
    mutex.unlock();
}

void Wlog::setColor(QString info)
{
#ifdef _WIN64
    HANDLE hCon = GetStdHandle(STD_OUTPUT_HANDLE); //获取缓冲区句柄;
    if (info.isEmpty())
    {
        SetConsoleTextAttribute(hCon, FOREGROUND_INTENSITY | FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);
    }
    else if (info.contains("[INFO"))
    {
        SetConsoleTextAttribute(hCon, FOREGROUND_INTENSITY | FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);
    }
    else if (info.contains("[SUCCESS"))
    {
        SetConsoleTextAttribute(hCon, FOREGROUND_INTENSITY | FOREGROUND_GREEN);
    }
    else if (info.contains("[ERROR"))
    {
        SetConsoleTextAttribute(hCon, FOREGROUND_INTENSITY | FOREGROUND_RED);
    }
    else if (info.contains("[FOCUS"))
    {
        SetConsoleTextAttribute(hCon, FOREGROUND_INTENSITY | FOREGROUND_RED | FOREGROUND_GREEN);
    }
#endif
}

此列中调用 qInstallMessageHandler(Wlog::loggerOutput)。

使用方法

#include <QCoreApplication>
#include "Wlog.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    Wlog::getInstance()->init();

    INFO_PRINT<<"info print";
    ERROR_PRINT<<"error print";
    SUCCESS_PRINT<<"success print";

    return a.exec();
}