2> 完成文本编辑器的保存工作

头文件

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QFontDialog>
#include <QMainWindow>
#include <QFont>
#include <QMessageBox>
#include <QDebug>
#include <QColorDialog>
#include <QColor>
#include <QFileDialog>
#include <QFile>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_fontbtn_clicked();

    void on_colorbtn_clicked();

    void on_openbtn_clicked();

    void on_savebtn_clicked();

private:
    Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

.cpp文件

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

//字体按钮对应的槽
void MainWindow::on_fontbtn_clicked()
{
    bool ok;
    QFont f = QFontDialog::getFont(&ok,
                         QFont("隶书",10,10,false),
                         this,
                         "选择字体");

    if(ok)
    {
        //ui->textEdit->setFont(f);
        ui->textEdit->setCurrentFont(f);
    }else
    {
        QMessageBox::information(this,
                                 "取消",
                                 "用户取消选择字体");
    }
}

void MainWindow::on_colorbtn_clicked()
{
    QColor c = QColorDialog::getColor(QColor("yellow"),
                                      this,
                                      "选择颜色");

    if(c.isValid())
    {
        ui->textEdit->setTextColor(c);

    }else
    {
        QMessageBox::information(this,
                                 "取消",
                                 "用户取消了选择颜色");
    }
}

void MainWindow::on_openbtn_clicked()
{
    QString fileName = QFileDialog::getOpenFileName(this,
                                                    "选择文件",
                                                    "./",
                                                    "All(*.*);;Image (*.png *.xpm *.hpg);;Text (*.txt)");

    if(fileName.isNull())
    {
        QMessageBox::information(this,"提示","用户取消了选择文件");
        return ;
    }

    qDebug()<<fileName;

    QFile file(fileName);
    if(!file.isOpen())
    {
        if(!file.open(QFile::ReadWrite))
        {
            QMessageBox::critical(this,"失败","文件打开失败");
            return;
        }
    }

    QByteArray msg = file.readAll();

    file.close();

    ui->textEdit->setText(msg);

}

void MainWindow::on_savebtn_clicked()
{
    QString fileName = QFileDialog::getSaveFileName(this,
                                                    "文件另存为",
                                                    "./",
                                                    "All(*.*);;Image (*.png *.xpm *.hpg);;Text (*.txt)");
    if(fileName.isNull())
    {
        QMessageBox::information(this,"提示","用户取消了保存文件");
        return ;
    }

    qDebug()<<fileName;

    QFile file(fileName);
    if(file.open(QFile::ReadWrite))
    {
        QByteArray msg = file.readAll();
        msg=ui->textEdit->toPlainText().toLocal8Bit();
        file.write(msg);
    }else
    {
        QMessageBox::information(this,"提示","文件另存为失败");
    }

}

3>

头文件

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTimerEvent>
#include <QTime>
#include <QTimer>
#include <QPushButton>
#include <QtTextToSpeech/QTextToSpeech>
#include <QVoice>
#include <QMessageBox>
#include <QElapsedTimer>

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();

    //时钟函数
    void timerEvent(QTimerEvent *e) override;

private:
    Ui::Widget *ui;
    QTimer *timer;
    int time_id;
    QTextToSpeech *speech = new QTextToSpeech(this);


private slots:
    //确定按钮
    void on_pushButton_clicked();

    //计时器事件函数
    void on_timer_timeout();

    //取消按钮
    void on_pushButton_2_clicked();
};
#endif // WIDGET_H

.cpp

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);

    this->timer=new QTimer;

    //0.1s检查一次
    time_id=startTimer(100);

     //连接定时器信号和自定义的槽函数
     connect(timer,&QTimer::timeout,this,&Widget::on_timer_timeout);

}

Widget::~Widget()
{
    delete ui;
}

//启动按钮
void Widget::on_pushButton_clicked()
{
    timer->start(100);
    ui->textEdit->setReadOnly(true);
    ui->lineEdit->setReadOnly(true);
}

//计时器函数
void Widget::on_timer_timeout()
{
    if(ui->lineEdit->text()==ui->label->text())
    {
        //播报员
        speech = new QTextToSpeech(this);
        QString text = ui->textEdit->toPlainText();
        speech->say(text);
    }
}

//时钟
void Widget::timerEvent(QTimerEvent *event)
{
    if(event->timerId()==time_id)
    {
    QDateTime sysDateTime=QDateTime::currentDateTime();
    QString dateTime=sysDateTime.toString("hh:mm:ss");
    ui->label->setText(dateTime);
    }
}

//停止
void Widget::on_pushButton_2_clicked()
{
    QMessageBox box(QMessageBox::Warning,"Warning","是否要重设闹钟",QMessageBox::Yes|QMessageBox::No);
           int ret = box.exec();
           if(ret==QMessageBox::Yes)
           {
               //关闭定时器
               timer->stop();
               //定时器关闭后行编辑器和文本编辑器重新有效
               ui->textEdit->setReadOnly(false);
               ui->lineEdit->setReadOnly(false);
               //清空之前设置的行文本编辑器
               ui->lineEdit->clear();
               speech->stop();
           }
}