滑动条之QSlider

//mydialog.h  
#ifndef MYDIALOG_H  
#define MYDIALOG_H  
#include <QDialog>  
class QLineEdit;  
class QSlider;  
class MyDialog : public QDialog  
{  
  Q_OBJECT  
public:  
  explicit MyDialog(QWidget *parent = 0);  
signals:  
public slots:  
  void setLineEditValue(int value);  
private:  
  QLineEdit *lineEdit;  
  QSlider *slider;  
};  
#endif // MYDIALOG_H  

//mydialog.cpp  
#include "mydialog.h"  
#include <QtGui/QLineEdit>  
#include <QtGui/QSlider>  
#include <QtGui/QHBoxLayout>  
MyDialog::MyDialog(QWidget *parent) :  
  QDialog(parent)  
{  
  lineEdit = new QLineEdit("50");  
  
  //新建一个水平方向的滑动条QSlider控件  
  slider = new QSlider(Qt::Horizontal);  
  //设置滑动条控件的最小值  
  slider->setMinimum(0);  
  //设置滑动条控件的最大值  
  slider->setMaximum(100);  
  //设置滑动条控件的值  
  slider->setValue(50);  
  
  //信号和槽 当滑动条的值发生改变时，即产生一个valueChanged(int)信号 设置QLineEdit控件的显示文本  
  connect(slider, SIGNAL(valueChanged(int)), this, SLOT(setLineEditValue(int)));  
  
  QHBoxLayout *layout = new QHBoxLayout();  
  layout->addWidget(lineEdit);  
  layout->addWidget(slider);  
  
  this->setLayout(layout);  
  this->resize(200, 50);  
  this->setWindowTitle("QSliderDemo");  
}  
  
void MyDialog::setLineEditValue(int value)  
{  
  int pos = slider->value();  
  QString str = QString("%1").arg(pos);  
  lineEdit->setText(str);  
}  

//main.cpp  
#include <QtGui/QApplication>  
#include "mydialog.h"  
int main(int argc, char *argv[])  
{  
  QApplication a(argc, argv);  
  MyDialog dialog;  
  dialog.show();  
  return a.exec();  
}