QT 重定向qdebug输出到自绘界面

因为在嵌入式中调试qt需要查看输出信息,特意写了一个类用户便捷查看qdebug信息

界面如下:

提供了开始,停止,保存,清空,退出功能,具体代码下文给出

文件如下

#ifndef QDEBUGREDIRECT_H
#define QDEBUGREDIRECT_H
/**qdebug  重定向类 定向到界面控件*李吉磊 2023.12.7*
*/#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QPushButton>
#include <QTextEdit>
#include <QWidget>
#include <QMutex>class qDebugRedirect : public QObject
{Q_OBJECT
public:qDebugRedirect();void showWidget();    //展示界面void closeWidget();    //关闭界面static void myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg);private:void InitWidget();void StartRedirect();     //启动注册void StopRedirect();      //停止注册void Save2File();         //将界面文本内容保存到本地QWidget * m_widget;  //界面QTextEdit * m_Edit;QMutex m_mutex;
};#endif // QDEBUGREDIRECT_H

#include "qdebugredirect.h"
#include <QGridLayout>
#include <QDebug>
#include <QDateTime>
#include <QDir>
qDebugRedirect * g_qDebugRedirect;qDebugRedirect::qDebugRedirect()
{m_widget = nullptr;g_qDebugRedirect = this;//下面两行为在构造该类时启动重定向,后续只要展示出界面即可查看信息InitWidget();StartRedirect();
}void qDebugRedirect::myMessageOutput(QtMsgType type, const QMessageLogContext &context, const QString &msg)
{// 加锁g_qDebugRedirect->m_mutex.lock();//信息分类QString strMsg("");QByteArray localMsg = msg.toLocal8Bit();switch(type){case QtDebugMsg:strMsg = QString("Debug:");break;case QtInfoMsg:strMsg = QString("Info:");break;case QtWarningMsg:strMsg = QString("Warning:");break;case QtCriticalMsg:strMsg = QString("Critical:");break;case QtFatalMsg:strMsg = QString("Fatal:");break;default:break;}//文件名、函数名、行数strMsg += QString("Function: %1  File: %2  Line: %3 ").arg(context.function).arg(context.file).arg(context.line);// 时间和内容QString strDateTime = QDateTime::currentDateTime().toString("hh:mm:ss");QString strMessage = QString("%1 %2:%3").arg(strDateTime).arg(strMsg).arg(localMsg.constData());int maxLen = 2*1024*1024;int len = g_qDebugRedirect->m_Edit->toPlainText().length();if(len > maxLen)g_qDebugRedirect->m_Edit->clear();g_qDebugRedirect->m_Edit->append(strMessage);g_qDebugRedirect->m_Edit->moveCursor(QTextCursor::End);// 解锁g_qDebugRedirect->m_mutex.unlock();}void qDebugRedirect::StartRedirect()
{qInstallMessageHandler(myMessageOutput);
}void qDebugRedirect::StopRedirect()
{qInstallMessageHandler(nullptr);
}void qDebugRedirect::InitWidget()
{if(m_widget == nullptr){m_widget = new QWidget();QGridLayout * glay = new QGridLayout();glay->setSpacing(0);glay->setMargin(0);glay->setContentsMargins(0,0,0,0);m_widget->setLayout(glay);QPushButton * pbClose = new QPushButton();  //关闭界面按钮pbClose->setText("close");QObject::connect(pbClose,&QPushButton::clicked,this,[=](){closeWidget();//qDebug() << "close";});glay->addWidget(pbClose,0,8,1,1);QPushButton * pbBegin = new QPushButton();  //开始按钮pbBegin->setText("start");QObject::connect(pbBegin,&QPushButton::clicked,this,[=](){StartRedirect();});glay->addWidget(pbBegin,1,0,1,2);QPushButton * pbEnd = new QPushButton();    //结束按钮pbEnd->setText("stop");QObject::connect(pbEnd,&QPushButton::clicked,this,[=](){StopRedirect();});glay->addWidget(pbEnd,1,2,1,2);QPushButton * pSave = new QPushButton();    //保存按钮pSave->setText("save");QObject::connect(pSave,&QPushButton::clicked,this,[=](){Save2File();});glay->addWidget(pSave,1,4,1,2);QPushButton * pClear = new QPushButton();    //清理按钮pClear->setText("clear");QObject::connect(pClear,&QPushButton::clicked,this,[=](){m_Edit->clear();});glay->addWidget(pClear,1,8,1,1);//展示控件m_Edit = new QTextEdit();glay->addWidget(m_Edit,2,0,6,9);//m_widget->setWindowFlag(Qt::WindowStaysOnTopHint,true);//m_widget->setWindowFlags(Qt::FramelessWindowHint);//m_widget->setWindowModality(Qt::ApplicationModal);m_widget->resize(800,600);}
}void qDebugRedirect::showWidget()    //展示界面
{InitWidget();m_widget->show();
}void qDebugRedirect::closeWidget()    //关闭界面
{if(m_widget){m_widget->close();delete m_widget;m_widget = nullptr;}
}void qDebugRedirect::Save2File()
{//创建log文件夹qDebug() << "currentPath : " << QDir::currentPath();QDir dir("log");if (!dir.exists()){QDir dir;bool b = dir.mkdir("log");qDebug() << "dir.mkdir(\"log\") = "  << b;}//创建log文件QString currentDate = QDateTime::currentDateTime().toString("yyyyMMdd");QString logName = "log" + currentDate + ".txt";QString logFileName = "log/" + logName;//写入文件QFile file(logFileName);if (!file.open(QIODevice::WriteOnly | QIODevice::Append)){qDebug() << "file.open : " << logFileName << "faild";file.close();return ;}qDebug() << "file.open : " << logFileName << "succeed";QTextStream stream(&file);stream << m_Edit->toPlainText() << "\r\n";;file.flush();file.close();
}

使用方法也很简单

先构造

qDebugRedirect * m_widget;

m_widget = new qDebugRedirect();

然后展示界面或关闭界面

m_widget->showWidget();   展示界面

m_widget->closeWidget();  关闭界面

当然了界面自带close 按钮 或者 窗体的x 退出按钮均可退出