QT 4.7 控件间 互相发送消息例子

#include <QWidget>class WidgetTest : public QWidget

#include <qlcdnumber.h>
#include <qfont.h>
#include <QVBoxLayout>
#include <QtGui/QApplication>

{

    Q_OBJECT

public:

    explicit WidgetTest(QWidget *parent = 0);

   // ~Widget();

private:

};

WidgetTest::WidgetTest(QWidget *parent) :
    QWidget(parent)
{
    QPushButton *quit = new QPushButton( "Quit", this);
    quit->setFont(QFont("Times", 10, QFont::Bold ));
    connect( quit, SIGNAL(clicked()), qApp, SLOT(quit()) );
s
    QLCDNumber *lcd  = new QLCDNumber( 10, this);
    QSlider * slider = new QSlider(Qt::Horizontal, this);
    slider->setRange( 0, 100 );
    slider->setValue( 0 );
    QVBoxLayout* testLayout = new QVBoxLayout;
    this->setLayout(testLayout);
    testLayout->addWidget(quit);
    testLayout->addWidget(lcd);
    testLayout->addWidget(slider);
    connect( slider, SIGNAL(valueChanged(int)), lcd,SLOT(display(int)) );
}
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    WidgetTest w(0);
    w.show();
    return a.exec();
}