qt学习最简单的例子

/*
hello.cpp
ubuntu 7.10
*/

#include <QApplication>
#include <QPushButton>
#include <QWidget>
#include <QVBoxLayout>
#include <QLabel>

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

{
        QApplication app(argc, argv);
        QPushButton* hello=new QPushButton(QObject::tr("hello world!"),0);

        QWidget* pWidget = new QWidget;
        QLabel label(pWidget);
        QPushButton* btn = new QPushButton(QObject::tr("close"), pWidget);
        QVBoxLayout* layout = new QVBoxLayout;
        layout->addWidget(&label);
        layout->addWidget(btn);
        layout->addWidget(hello);
        pWidget->setLayout(layout);
        QObject::connect(btn, SIGNAL(clicked()), pWidget, SLOT(close()));
        pWidget->show();
        return app.exec();
}

编译步骤：
helight@helight-desktop:~/linux/qt-test/hello$ qmake -project
helight@helight-desktop:~/linux/qt-test/hello$ qmake
helight@helight-desktop:~/linux/qt-test/hello$ make
g++ -c -pipe -g -Wall -W -D_REENTRANT -DQT_SHARED -DQT_GUI_LIB -DQT_CORE_LIB -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I. -I. -I. -o hello.o hello.cpp
g++  -o hello hello.o    -L/usr/lib -lQtGui -lQtCore -lpthread
helight@helight-desktop:~/linux/qt-test/hello$ ./hello