QLabel ------------------------------------------------------------------------

//#include"mainwindow.h"

#include
    

#include
    

intmain(intargc,char*argv[])

{

QApplicationapp(argc,argv);

//MainWindoww;

//w.show();

QLabel*label=newQLabel("helloQT");

QLabel*label2=newQLabel("
hello""
     
      QT
     
");

label->show();

label2->show();

returnapp.exec();

} QPushButton ------------------------------------------------------------------------

#include"mainwindow.h"

#include
    

#include
    
      //add include file
    

intmain(intargc,char*argv[])

{

QApplicationa(argc,argv);

//MainWindoww;

//w.show();

QPushButton*button=newQPushButton("Quit");

//add siganl deal QObject::connect(button,SIGNAL(clicked()),&a,SLOT(quit()));

button->show();

returna.exec();

} QSpinBox,QSlider ------------------------------------------------------------------------

#include"mainwindow.h"

#include
    

#include
    

#include
    

#include
    

intmain(intargc,char*argv[])

{

QApplicationa(argc,argv);

//MainWindoww;

//w.show();

QWidget*window=newQWidget();

window->setWindowTitle("EnterYourYear:");

QSpinBox*spinbox=newQSpinBox();

QSlider*slider=newQSlider(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*boxlayout=newQHBoxLayout();

boxlayout->addWidget(spinbox);

boxlayout->addWidget(slider);

window->setLayout(boxlayout);

window->show();

returna.exec();

}