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：