主函数

//main.cpp#include "mainwindow.h"
#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);MainWindow w;w.show();w.resize(900,600);//设置主窗口尺寸return a.exec();
}

// mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWindow)
{ui->setupUi(this);//功能函数调用MenuBar();ToolBar();CentralWidget();StatusBar();this->setWindowTitle("无标题文档");}
//异常退出的可能性
//1.死循环,
//2.空指针
//3.释放异常void MainWindow:: MenuBar()
{//菜单栏QMenuBar *menuBar=this->menuBar();QMenu* fileMenu=menuBar->addMenu("File");QMenu* editMenu=menuBar->addMenu("Edit");QMenu* helpMenu=menuBar->addMenu("Help");file=fileMenu->addAction(QIcon("://simpleword_images/filenew.png"),"file");save=fileMenu->addAction(QIcon("://simpleword_images/filesave.png"),"save");openFile=fileMenu->addAction(QIcon("://simpleword_images/fileprint.png"),"open");editMenu->addAction(QIcon("://simpleword_images/editcopy.png"),"copy");editMenu->addAction(QIcon("://simpleword_images/editpaste.png"),"paste");helpMenu->addAction(QIcon("://simpleword_images/textright.png"),"catalogue");helpMenu->addAction(QIcon("://simpleword_images/textunder.png"),"index");connect(save,QAction::triggered,this,MainWindow::saveFile);connect(file,QAction::triggered,this,[=](){if(this->windowTitle()=="无标题文档"){if(Qtext->toPlainText()!=""){if(QMessageBox ::question(this,"?","请问是否需要保存")==QMessageBox::Yes){this->saveFile();this->setWindowTitle("无标题文档");}}}else{if(QMessageBox ::question(this,"?","请问是否需要保存")==QMessageBox::Yes)this->saveFile();}Qtext->clear();});connect(openFile,QAction::triggered,this,[=](){if(this->windowTitle()=="无标题文档"){if(QMessageBox ::question(this,"?","请问是否需要保存")==QMessageBox::Yes)this->saveFile();}else{this->saveFile();}//打开文件QString filePath =QFileDialog::getOpenFileName(this);//创建文件对象this->setWindowTitle(filePath);QFile f(filePath);//将文本内容输出if(f.open(QIODevice::ReadWrite)){QTextStream s(&f);QString data=s.readAll();Qtext->setText(data);}});
}void MainWindow::ToolBar()
{//工具栏QToolBar*toolBar=this->addToolBar("tool");toolBar->addAction(file);toolBar->addAction(save);toolBar->addAction(openFile);QLabel*fontlabel=new QLabel(" 字体： ",this);QFontComboBox* fontcombobox=new QFontComboBox(this);toolBar->addWidget(fontlabel);toolBar->addWidget(fontcombobox);QLabel*fontsizelabel=new QLabel(" 字号： ",this);QComboBox *fontsizecombobox=new QComboBox(this);toolBar->addWidget(fontsizelabel);toolBar->addWidget(fontsizecombobox);toolBar->addSeparator();int i=1;while(i<=20){fontsizecombobox->addItem(QString::number(i));i++;}QPushButton *fontBold=new QPushButton(this);fontBold->setIcon(QIcon("://simpleword_images/textbold.png"));toolBar->addWidget(fontBold);QPushButton *itBold=new QPushButton(this);itBold->setIcon(QIcon("://simpleword_images/textitalic.png"));toolBar->addWidget(itBold);QPushButton *color=new QPushButton(this);color->setIcon(QIcon("://simpleword_images/true-color.png"));toolBar->addWidget(color);//信号与槽//lambda表达式，=值传递（不可修改变量值），&引用传递（可以修改变量值），可以利用上面的局部变量以及thisconnect(fontBold,QPushButton::clicked,this,[=](){Qtext->setFontWeight(Qtext->fontWeight()==QFont::Normal?QFont::Bold:QFont::Normal);});//如果第三个参数是this，则this可以不写connect(itBold,QPushButton::clicked,[=](){Qtext->setFontItalic(Qtext->fontItalic()==true?false:true);});connect(fontcombobox,QFontComboBox::currentFontChanged,this,MainWindow::setFont);connect(fontsizecombobox,QComboBox::currentTextChanged,this,MainWindow::setsize);//color->setCheckable(true);//设置当前按钮可以被选中connect(color,QPushButton::clicked,[=](){//qDebug()<<checked;//QColorDialog *dialog=new QColorDialog();//QColorDialog是Qt准备好的颜色选择器QColor color =QColorDialog::getColor();QTextCharFormat format;//创建格式对象属性format.setForeground(QBrush(color));//设置格式对象属性Qtext->mergeCurrentCharFormat(format);//设置选中文本为该格式//dialog->show();//非模态对话框显示//dialog->exec();//模态对话框显});
}void MainWindow::saveFile()
{QString filePath=this->windowTitle();if(this->windowTitle()=="无标题文档"){filePath=QFileDialog::getSaveFileName();qDebug()<<filePath;}//创建文件对象QFile f(filePath);//获取编辑区文本QString data=Qtext->toPlainText();//将data输出到文件中if(f.open(QIODevice::ReadWrite)){QTextStream textStream(&f);textStream<<data;this->setWindowTitle(filePath);}
}void MainWindow:: CentralWidget()
{//核心控件Qtext=new QTextEdit(this);this->setCentralWidget(Qtext);
}void MainWindow:: StatusBar()
{//状态栏QStatusBar*statusBar=this->statusBar();timelabel=new QLabel("时间",this);statusBar->addWidget(timelabel);QTimer*timer =new QTimer(this);timer->start(1000);connect(timer,  QTimer::timeout,this,MainWindow::setTime);
}void MainWindow::setFont(QFont font)
{this->Qtext->setFontFamily(font.toString());
}void MainWindow::setsize(QString size)
{this->Qtext->setFontPointSize(size.toInt());
}void MainWindow::setTime()
{QString time= QDateTime::currentDateTime().toString("yyyy-MM-dd HH:mm:ss");timelabel->setText("时间"+time);
}MainWindow::~MainWindow()
{delete ui;
}

//  mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include<QDateTime>
#include<QDebug>
#include<QDialog>
#include<QColor>
#include<QColorDialog>
#include <QMainWindow>
#include<QTextEdit>
#include<QLabel>
#include<QFile>
#include<QFontComboBox>
#include<QPushButton>
#include<QTimer>
#include<QFileDialog>
#include<QMessageBox>
#include<QString>namespace Ui {
class MainWindow;
}class MainWindow : public QMainWindow
{Q_OBJECTpublic:explicit MainWindow(QWidget *parent = 0);void setTime();QAction*file;QAction*save;QAction*openFile;QLabel*timelabel;QTextEdit *Qtext;void setsize(QString size);void setFont(QFont font);void saveFile();void MenuBar();void ToolBar();void CentralWidget();void StatusBar();~MainWindow();private:Ui::MainWindow *ui;
};#endif // MAINWINDOW_H