QT4 简介代码

（1）Hello Qt!

#include <QtGui/QApplication>

#include<QLabel>

 

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

{

    QApplication a(argc, argv);

 

    QLabel *label = new QLabel("Hello Qt!");

    label->show();

    return a.exec();

}

 

（2）连接信号和响应函数

#include <QtGui/QApplication>

#include<QPushButton>

 

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

{

    QApplication a(argc, argv);

 

    QPushButton *button = new QPushButton("Quit");

    QObject::connect(button,SIGNAL(clicked()),&a,SLOT(quit()));

    button->show();

    return a.exec();

}

（3）控件的几何排序

#include <QtGui/QApplication>

#include<QHBoxLayout>

#include<QSlider>

#include<QSpinBox>

 

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

{

    QApplication a(argc, argv);

 QWidget *window = new QWidget;

 window->setWindowTitle("Enter Your Age");

 

    QSpinBox *spinBox = new QSpinBox;

 QSlider *slider = new QSlider(Qt::Horizontal);

    spinBox->setRange(0,130);

    slider->setRange(0,130);

    QObject::connect(spinBox,SIGNAL(valueChanged(int)),

                        slider,SLOT(setValue(int)));

    QObject::connect(slider,SIGNAL(valueChanged(int)),

                     spinBox,SLOT(setValue(int)));

    spinBox->setValue(35);

    QHBoxLayout *layout = new QHBoxLayout;

    layout->addWidget(spinBox);

    layout->addWidget(slider);

    window->setLayout(layout);

    window->show();

 

    return a.exec();

}