QT 4-9滑动条

dialog.h

#ifndef DIALOG_H

#define DIALOG_H

#include <QDialog>

#include<QLabel>

#include<QSlider>

class Dialog : public QDialog

{

    Q_OBJECT

public:

    Dialog(QWidget *parent = 0);

    ~Dialog();

public slots:

    void setLabelText(int pos);

private:

    QLabel*label;

    QSlider*slider;

};

#endif // DIALOG_H

dialog.cpp

#include "dialog.h"

Dialog::Dialog(QWidget *parent)

    : QDialog(parent)

{

    this->resize(320,100);

    slider=new QSlider(Qt::Horizontal,this);

    slider->setMinimum(0);

     slider->setMaximum(300);

    slider->setValue(50);

    slider->update();

    label= new QLabel(this);

    QFont font;

    font.setPointSize(14);

    label->setFont(font);

    label->setAlignment(Qt::AlignHCenter);

    label->setText("50");

    label->setGeometry(20,20,50,25);

    slider->setGeometry(80,25,200,20);

    connect(slider,SIGNAL(valueChanged(int)),this,SLOT(setLabelText(int)));

    this->setWindowTitle("QSliderDemo");

}

Dialog::~Dialog()

{

}

 void Dialog::setLabelText(int pos)

 {

QString str=QString("%1").arg(pos);

label->setText(str);

 }

main.cpp

#include "dialog.h"

#include <QApplication>

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    Dialog w;

    w.show();

    return a.exec();

}