文章目录
一、单独作为一个简单的项目(可以占用QMainWindow)二、大项目中作为菜单栏的一个功能（只能用QDialog）一、单独作为一个简单的项目(可以占用QMainWindow)
//LogWidget.h (mainwindow.h)
#ifndef LogWidget_H#define LogWidget_H#include <QMainWindow>#include <QDebug>#include <QFile>namespace Ui {class LogWidget;}class LogWidget : public QMainWindow{Q_OBJECTpublic:explicit LogWidget(QWidget *parent = 0);~LogWidget();private slots: //槽函数void on_pushButton_clicked();private:Ui::LogWidget *ui;};#endif // LogWidget_H
//LogWidget.cpp (mainwindow.cpp)
#include "LogWidget.h"#include "ui_LogWidget.h"//uic工具自动由xx.ui生成ui_xxx.h//构造函数LogWidget::LogWidget(QWidget *parent) :QMainWindow(parent),ui(new Ui::LogWidget){ui->setupUi(this);}//析构函数LogWidget::~LogWidget(){delete ui;}void LogWidget::on_pushButton_clicked(){QString displayString;QFile file("C:\\Users\\zwc11\\Yeecoh\\log.txt"); //目标文件路径if(!file.open(QIODevice::ReadOnly | QIODevice::Text)){qDebug()<<"Can't open the file!";}while(!file.atEnd()){QByteArray line = file.readLine();QString str(line);qDebug()<< str;displayString.append(str);}ui->textEdit->clear();ui->textEdit->setPlainText(displayString);}
//LogWidget.ui (xml格式) (mainwindow.ui)
<?xml version="1.0" encoding="UTF-8"?><ui version="4.0"><class>LogWidget</class><widget class="QMainWindow" name="LogWidget"><property name="geometry"><rect><x>0</x><y>0</y><width>1179</width><height>640</height></rect></property><property name="windowTitle"><string>LogWidget</string></property><widget class="QWidget" name="centralWidget"><widget class="QTextEdit" name="textEdit"><property name="geometry"><rect><x>10</x><y>90</y><width>1151</width><height>491</height></rect></property></widget><widget class="QPushButton" name="pushButton"><property name="geometry"><rect><x>390</x><y>20</y><width>301</width><height>51</height></rect></property><property name="text"><string>读取日志</string></property></widget></widget><widget class="QMenuBar" name="menuBar"><property name="geometry"><rect><x>0</x><y>0</y><width>1179</width><height>22</height></rect></property></widget><widget class="QToolBar" name="mainToolBar"><attribute name="toolBarArea"><enum>TopToolBarArea</enum></attribute><attribute name="toolBarBreak"><bool>false</bool></attribute></widget><widget class="QStatusBar" name="statusBar"/></widget><layoutdefault spacing="6" margin="11"/><resources/><connections/></ui>
// fileRead.pro
QT += core guigreaterThan(QT_MAJOR_VERSION, 4): QT += widgetsTARGET = fileRead //.pro文件名TEMPLATE = appDEFINES += QT_DEPRECATED_WARNINGSSOURCES += main.cpp\LogWidget.cppHEADERS += LogWidget.hFORMS += LogWidget.ui
//main.cpp
#include "LogWidget.h"#include <QApplication>int main(int argc, char *argv[]){QApplication a(argc, argv);LogWidget w;w.show();return a.exec();}
二、大项目中作为菜单栏的一个功能（只能用QDialog）
//LogWidget.h
#ifndef LogWidget_H#define LogWidget_H#include <QDialog>#include <QDebug>#include <QFile>namespace Ui {class LogWidget;}class LogWidget : public QDialog //区别只有这里换成继承自QDialog类{Q_OBJECTpublic:explicit LogWidget(QWidget *parent = 0);~LogWidget();private slots:void on_pushButton_clicked();private:Ui::LogWidget *ui;};#endif // LogWidget_H
//LogWidget.cpp
#include "LogWidget.h"#include "ui_LogWidget.h"LogWidget::LogWidget(QWidget *parent) :QDialog(parent), //区别就是这里换成QDialogui(new Ui::LogWidget){ui->setupUi(this);}LogWidget::~LogWidget(){delete ui;}void LogWidget::on_pushButton_clicked(){QString displayString;QFile file("C:\\Users\\zwc11\\Yeecoh\\log.txt");if(!file.open(QIODevice::ReadOnly | QIODevice::Text)){//qDebug()<<"Can't open the file!"; //如果qDebug()内容一边写入log.txt，一边读取到文件末尾，则会死循环不停地写入}//日志文件会在几秒里扩充到上百MBwhile(!file.atEnd()){QByteArray line = file.readLine();QString str(line);//qDebug()<< str;displayString.append(str);}ui->textEdit->clear();ui->textEdit->setPlainText(displayString);}
//LogWidget.ui：与上文完全相同
//YeecohWindow.cpp (mainwindow.cpp)
void YeecohWindow::log(){QString fileName = QFileDialog::getOpenFileName(this,tr("打开详细日志"), //打开文件窗口名称"C:\\Users\\zwc11\\Yeecoh", //默认搜索路径tr("txt(*.txt);;All files(*.*)")); //过滤器if (fileName.isEmpty()) {QMessageBox::warning(this, "Warning!", "Failed to open the log.txt !");}else{//重点设计一下这里LogWidget win;win.exec();}}
更新：
LogWidget.cpp
//add by Edward,-06-25#include "LogWidget.h"#include "ui_LogWidget.h"#include <QStandardPaths>LogWidget::LogWidget(QWidget *parent) :QDialog(parent),ui(new Ui::LogWidget){ui->setupUi(this);}LogWidget::~LogWidget(){delete ui;}void LogWidget::on_pushButton_clicked(){QString displayString;//QFile file("C:/Users/zwc11/Yeecoh/log.txt"); //调试用，工位绝对路径,//QFile file("%HOMEPATH%/Yeecoh/log,txt");//调试用，使用家目录环境变量，读取失败//QFile file(QStandardPaths::writableLocation(QStandardPaths::HomeLocation)+"/Yeecoh/log.txt"); //旧写法，选择要读取的文件(使用Qt家目录语法)QFile file(QCoreApplication::applicationDirPath()+"/Yeecoh/log.txt");//新写法，选择要读取的文件,add by Edward,-07-01if(!file.open(QIODevice::ReadOnly | QIODevice::Text)){//qDebug()<<"Can't open the file!";}while(!file.atEnd()){QByteArray line = file.readLine();QRegExp rx("(.*Debug.*)|(.*Info.*)|(.*Warning.*)|(.*Critical.*)|(.*Fatal.*)");QString str(line);if(rx.exactMatch(str)) {//判断目标与正则表达式是否匹配//qDebug()<< str;displayString.append(str);}else{//什么也不做，不显示内容}}ui->textEdit->clear();ui->textEdit->setPlainText(displayString);}
日志优化：去除读取文件的按钮，去除右上角？按钮
LogWidget.cpp
//add by Edward,-06-25#include "QMainWindow"#include "LogWidget.h"#include "ui_LogWidget.h"#include <QStandardPaths>LogWidget::LogWidget(QWidget *parent) :QDialog(parent),ui(new Ui::LogWidget){ui->setupUi(this);this->setWindowFlags(Qt::CustomizeWindowHint|Qt::WindowCloseButtonHint); //把QMenubar右上角的？按钮隐藏，add by Edward,-08-03QString displayString;//QFile file(QStandardPaths::writableLocation(QStandardPaths::HomeLocation)+"/Yeecoh/log.txt"); //旧写法，选择要读取的文件(使用Qt家目录语法)//QFile file(QCoreApplication::applicationDirPath()+"/Yeecoh/log.txt");//新写法，选择要读取的文件,add by Edward,-07-01#ifdef WIN32QFile file(QStandardPaths::writableLocation(QStandardPaths::HomeLocation)+"/AppData/Local/Yeecoh/log.txt");//动态数据不能放在C盘ProgramFiles下，将Yeecoh目录放在隐藏目录AppData/Local下，add by Edward,-08-02#elseQFile file(QStandardPaths::writableLocation(QStandardPaths::HomeLocation)+"/Yeecoh/log.txt");//动态数据放在home/用户名/目录下,add by Edward,-08-03#endifif(!file.open(QIODevice::ReadOnly | QIODevice::Text)){//qDebug()<<"Can't open the file!";}while(!file.atEnd()){QByteArray line = file.readLine();QRegExp rx("(.*Debug Message.*)|(.*Info Message.*)|(.*Warning Message.*)|(.*Critical Message.*)|(.*Fatal Message.*)"); //过滤规则QString str(line);if(rx.exactMatch(str)) {//判断目标与正则表达式是否匹配//qDebug()<< str;displayString.append(str);}else{//正则匹配条件不符合，则什么也不做，不显示内容}}ui->textEdit->clear();ui->textEdit->setPlainText(displayString);}LogWidget::~LogWidget(){delete ui;}
