第一题、使用qss，通过线程，使进度条自己动起来

mythread.h

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QObject>
#include <QThread>
#include <QDebug>

class mythread : public QThread
{
    Q_OBJECT
public:
    mythread(QObject* parent=nullptr);
private:
    QThread* thread;
    int i;
protected:
    void run() override;

 signals:
    void send(int i);
};

#endif // MYTHREAD_H

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <mythread.h>

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

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

protected slots:
    void rcv(int i);

private:
    Ui::Widget *ui;
    mythread* thread;
};
#endif // WIDGET_H

mythread.cpp

#include "mythread.h"

mythread::mythread(QObject *parent)
    :i(0)
{
}

void mythread::run()
{
    while(1){
        emit send(i);
        i++;
        //qDebug()<<"hhh";
        if(i>=99)
        {
            i=0;
        }
        this->usleep(1000);
    }
}

 widget.cpp

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

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

    QString qss = R"(
        QSlider::groove:horizontal {
            background-color: #f0f0f0;  /* 滑轨的背景色为灰白色 */
            height: 10px;  /* 滑轨的高度增大 */
            border-radius: 5px;  /* 滑轨的圆角 */
        }

        QSlider::sub-page:horizontal {
            background-color: qlineargradient(x1:0, y1:0, x2:1, y2:0, stop:0 #6a11cb, stop:1 #2575fc);  /* 滑块左侧的渐变背景色 */
            height: 10px;  /* 滑块左侧的高度增大 */
            border-radius: 5px;  /* 滑块左侧的圆角 */
        }

        QSlider::handle:horizontal {
            background-color: #ffffff;  /* 滑块手柄的背景色 */
            width: 24px;  /* 滑块手柄的宽度增大 */
            height: 24px;  /* 滑块手柄的高度增大 */
            margin: -7px 0;  /* 滑块手柄的垂直居中调整 */
            border-radius: 12px;  /* 滑块手柄的圆角增大 */
            border: 2px solid #cccccc;  /* 滑块手柄的边框 */
        }
    )";
    ui->horizontalSlider->setStyleSheet(qss);

     thread=new mythread(this);
     thread->start();
     QObject::connect(thread,&mythread::send,this,&Widget::rcv);
}

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

void Widget::rcv(int i)
{
    ui->horizontalSlider->setValue(i);
}

运行截图；

 

第二题；实现大文件的拷贝

mythread.h

#ifndef MYTHREAD_H
#define MYTHREAD_H

#include <QObject>
#include <QThread>
#include <QDebug>
#include <QFile>
#include <QMouseEvent>
#include <QFileDialog>
#include <QDropEvent>

class mythread : public QThread
{
    Q_OBJECT
public:
    mythread(QObject* parent=nullptr);

    void run() override;

    void fileio();

public slots:
    void rcv(QString filename);

private:
    QString filename;
   // QFile file;

};

#endif // MYTHREAD_H

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QMoveEvent>
#include <QDragMoveEvent>
#include <QDragEnterEvent>
#include <QMimeData>
#include <QFileDialog>
#include <QDebug>
#include <mythread.h>
#include <QDropEvent>

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

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

protected:
    void dragEnterEvent(QDragEnterEvent *event);
    void dropEvent(QDropEvent *event) override;


private:
    Ui::Widget *ui;
    QString filename;
    mythread* thread;

signals:
    void send(QString filename);
};
#endif // WIDGET_H

mythread.cpp

#include "mythread.h"

mythread::mythread(QObject* parent)
{

}

void mythread::run()
{

    QFile file1;
    file1.setFileName(filename);
    file1.open(QIODevice::ReadOnly);
    QFile file2;

    QFileInfo fileInfo(filename);
    QString file_end = fileInfo.fileName();//获取文件名

    QString path="D:/QTproject/"+file_end;//拼接文件路径+文件名

    file2.setFileName(path);
    file2.open(QIODevice::WriteOnly);
    double size=0;
    while(1)
    {
        char arr[1024]="";
        int res=file1.read(arr,1024);
        if(res==0){qDebug()<<"传输数据大小: "<<size;return;}
        file2.write(arr,1024);
        size+=res;
       // qDebug()<<"传输数据大小: "<<size;
    }

    file1.close();
    file2.close();
}

void mythread::fileio()
{

}


void mythread::rcv(QString filename)
{
    qDebug()<<filename;
    this->filename=filename;
}

widget.cpp

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

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    this->setAcceptDrops(1);

    thread=new mythread(this);
    QObject::connect(this,&Widget::send,thread,&mythread::rcv);


}

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

void Widget::dragEnterEvent(QDragEnterEvent *event)
{

    event->acceptProposedAction();

}

void Widget::dropEvent(QDropEvent *event)
{
    const QMimeData* mimedata=event->mimeData();//获取文件路径

    QList<QUrl> list=mimedata->urls();//获取所有的文件地址

    QUrl url=list[0];//获取第几个文件具体地址

    filename=url.toLocalFile();//转化成字符串类型

    emit send(filename);

    thread->start();
}

 运行截图：