QT进度条QProgressBar的练习（定制QProgressBar，单独成为一个控件）

#ifndef PROGRESSBAR_H
#define PROGRESSBAR_H
#include <QProgressBar>
class QString;
class ProgressBar: public QProgressBar
{
Q_OBJECT
public:
ProgressBar(QWidget *parent = 0):QProgressBar(parent){}
QString strText;
public slots:
void stepOne();

};

#endif // PROGRESSBAR_H

#include "progressbar.h"
#include <QString>
void ProgressBar::stepOne()
{
if(this->value()+1 <= this->maximum())
{
this->setValue(this->value()+1);

strText = "QProgressBar Test : "+this->text();
this->setWindowTitle(strText);
}
else
{
this->setValue(this->minimum());
}
}

#include <QApplication>
#include <QTimer>
#include "progressbar.h"

int main(int argc, char**argv)
{
QApplication app(argc, argv);

//progressBar
ProgressBar *progressBar = new ProgressBar;
progressBar->setWindowTitle("QProgressBar Test");
progressBar->resize(400,40);
progressBar->setMaximum(100);
progressBar->setMinimum(0);
progressBar->setValue(0);

//define a timer
QTimer *timer = new QTimer;
timer->start(500);
QObject::connect(timer, SIGNAL(timeout()), progressBar, SLOT(stepOne()));
progressBar->show();
return app.exec();
}