QT日志系统

今天给大家介绍下QT里面的日志系统，直接上代码

 #include <QApplication>
 #include <iostream>
 #include "ThorHardwareUtil/PLC/plc.h"
 #include "ThorHardwareUtil/crc.h"
 #include "ThorHardwareUtil/Warehouse/baseshelf.h"
 #include <QDebug>
 #include "opendoorthread.h"
 #include "TestProject/testform.h"
 #include <QtMessageHandler>
 #include <QFile>
 #include <QDir>
 #include <ThorUtil/confighelper.h>
 #include <thread>
 using namespace std;
 //写入信息到文件
 void WriteLog(QString str, QString LogType)
 {

     QString fileFolder= qApp->applicationDirPath()+"/log/"+QDateTime::currentDateTime().toString("yyyy-MM-dd");
     QDir dir(fileFolder);
     if(!dir.exists())
     {
         dir.mkpath(fileFolder);
     }
     QString filePath=QString("%1/%2.log").arg(fileFolder).arg(LogType);
     QString strToWrite="日志产生时间："+QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss");
     strToWrite.append(QString("\r\n日志消息：%1").arg(str));
     strToWrite.append("\r\n---------------------------------------------------------------------");
     QFile file(filePath);
     file.open(QIODevice::WriteOnly | QIODevice::Append);
     QTextStream text_stream(&file);
     text_stream <<strToWrite<<"\r\n";
     file.flush();
     file.close();
     //打印到控制台
     std::cout << strToWrite.toLocal8Bit().constData() << std::endl;
 }
 //注册函数
 void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
 {
     QString txtMessage = "";
     QString messageType = "";
     switch (type)    {
     case QtDebugMsg:    //调试信息提示
         messageType = "Debug";
         txtMessage = QString("Debug: %1 (%2:%3, %4)\n").arg(msg).arg(context.file).arg(QString::number(context.line)).arg(context.function);
         break;
     case QtInfoMsg:
         messageType = "Info";
         txtMessage = QString("Warning: %1 (%2:%3, %4)\n").arg(msg).arg(context.file).arg(QString::number(context.line)).arg(context.function);
         break;
     case QtWarningMsg:    //一般的warning提示
         messageType = "Waring";
         txtMessage = QString("Warning: %1 (%2:%3, %4)\n").arg(msg).arg(context.file).arg(QString::number(context.line)).arg(context.function);
         break;
     case QtCriticalMsg:    //严重错误提示
         messageType = "Critical";
         txtMessage = QString("Critical: %1 (%2:%3, %4)\n").arg(msg).arg(context.file).arg(QString::number(context.line)).arg(context.function);
         PostErrorMessage(txtMessage,messageType);
         break;
     case QtFatalMsg:    //致命错误提示
         messageType = "Fatal";
         txtMessage = QString("Fatal: %1 (%2:%3, %4)\n").arg(msg).arg(context.file).arg(QString::number(context.line)).arg(context.function);
         abort();
     }
     WriteLog(txtMessage, messageType);
 }
 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
     //注册监听级别函数
     qInstallMessageHandler(myMessageOutput);

      qDebug() << "debug";

     return a.exec();
 }

这样大家使用qDebug，qInfo，qCritical等打印信息就会分类输出到日志文件里面，方便查看

注意：release模式下无法打印QMessageLogContext的具体内容，因为qt默认把release给取消了，需要在pro文件里面加上DEFINES += QT_MESSAGELOGCONTEXT