03.06 QT

一、使用QSlider设计一个进度条，并让其通过线程自己动起来

程序代码：

<1> Widget.h:

#ifndef WIDGET_H
#define WIDGET_H#include <QWidget>
#include <QThread>
#include "mythread.h"QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = nullptr);~Widget();private:Ui::Widget *ui;myThread* thread;public slots:private slots:void on_pushButton_clicked();void on_pushButton_2_clicked();
};
#endif // WIDGET_H

<2> Widget.cpp:

#include "widget.h"
#include "ui_widget.h"Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);thread = new myThread(this);//创建线程QObject::connect(thread,&myThread::pupdate,ui->horizontalSlider,&QSlider::setValue);QString qss = (R"(QSlider {background-color: transparent;}QSlider::groove:horizontal {background-color: #E0E0E0;height: 10px;border-radius: 5px;}QSlider::sub-page:horizontal {background: qlineargradient(x1:0, y1:0, x2:1, y2:0, stop:0 #6A11CB, stop:1 #2575FC);border-radius: 5px;box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.2);}QSlider::handle:horizontal {background: #FFFFFF;width: 16px;height: 16px;margin: -4px 0;border-radius: 8px;border: 2px solid #2575FC;box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.2);})");ui->horizontalSlider->setStyleSheet(qss);}Widget::~Widget()
{thread->terminate();delete ui;
}void Widget::on_pushButton_clicked()
{thread->start();
}void Widget::on_pushButton_2_clicked()
{thread->terminate();
}

<3> myThread.h:

#ifndef MYTHREAD_H
#define MYTHREAD_H#include <QThread>
#include <QSlider>class myThread : public QThread
{Q_OBJECT
public:myThread(QObject* parent = nullptr);protected:virtual void run() override;signals:void pupdate(int progress);private:};#endif // MYTHREAD_H

<4> myThread.cpp:

#include "mythread.h"myThread::myThread(QObject* parent):QThread(parent)
{}void myThread::run()
{int progress = 0;while(1){QThread::usleep(5000);progress = (progress + 1) % 101;emit pupdate(progress);}
}

运行结果：

二、

1. 使用 QFileDialog  + QT文件IO + QT线程。

2. 实现一个文件复制功能，要求能够复制大小超过800MB的文件。

3. 额外要求：在文件拷贝时，追加一个进度条显示拷贝了多少文件内容。

程序代码：

<1> Widget.h:

#ifndef WIDGET_H
#define WIDGET_H#include <QWidget>
#include <QThread>
#include "mythread.h"QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent = nullptr);~Widget();private:Ui::Widget *ui;myThread* thread;private slots:void on_pushButton_clicked();void on_pushButton_2_clicked();
};#endif // WIDGET_H

<2> Widget.cpp:

#include "widget.h"
#include "ui_widget.h"
#include <QFileDialog>
#include <QDebug>Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);thread = new myThread(this);connect(thread, &myThread::pupdate, ui->horizontalSlider, &QSlider::setValue);QString qss = (R"(QSlider {background-color: transparent;}QSlider::groove:horizontal {background-color: #E0E0E0;height: 10px;border-radius: 5px;}QSlider::sub-page:horizontal {background: qlineargradient(x1:0, y1:0, x2:1, y2:0, stop:0 #6A11CB, stop:1 #2575FC);border-radius: 5px;box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.2);}QSlider::handle:horizontal {background: #FFFFFF;width: 16px;height: 16px;margin: -4px 0;border-radius: 8px;border: 2px solid #2575FC;box-shadow: 0px 2px 4px rgba(0, 0, 0, 0.2);})");ui->horizontalSlider->setStyleSheet(qss);
}Widget::~Widget()
{thread->terminate();delete ui;
}void Widget::on_pushButton_clicked()
{QString sourceFilePath = QFileDialog::getOpenFileName(this, "Select Source File");if (sourceFilePath.isEmpty()) {return;}QString destinationFilePath = QFileDialog::getSaveFileName(this, "Select Destination File");if (destinationFilePath.isEmpty()) {return;}thread->setFilePaths(sourceFilePath, destinationFilePath);thread->start();
}void Widget::on_pushButton_2_clicked()
{thread->terminate();
}

<3> myThread.h:

#ifndef MYTHREAD_H
#define MYTHREAD_H#include <QThread>
#include <QFile>class myThread : public QThread
{Q_OBJECT
public:myThread(QObject* parent = nullptr);void setFilePaths(const QString &source, const QString &destination);protected:virtual void run() override;signals:void pupdate(int progress);private:QString sourcePath;QString destinationPath;
};#endif // MYTHREAD_H

<4> myThread.cpp:

#include "mythread.h"
#include <QFile>
#include <QDebug>myThread::myThread(QObject* parent): QThread(parent)
{
}void myThread::setFilePaths(const QString &source, const QString &destination)
{sourcePath = source;destinationPath = destination;
}void myThread::run()
{QFile sourceFile(sourcePath);QFile destinationFile(destinationPath);if (!sourceFile.open(QIODevice::ReadOnly)) {qDebug() << "Failed to open source file";return;}if (!destinationFile.open(QIODevice::WriteOnly)) {qDebug() << "Failed to open destination file";sourceFile.close();return;}qint64 fileSize = sourceFile.size();qint64 totalBytesRead = 0;char buffer[4096];while (!sourceFile.atEnd()) {qint64 bytesRead = sourceFile.read(buffer, sizeof(buffer));destinationFile.write(buffer, bytesRead);totalBytesRead += bytesRead;int progress = static_cast<int>((totalBytesRead * 100) / fileSize);emit pupdate(progress);}sourceFile.close();destinationFile.close();
}

运行结果：