install Qt5.4 creater in ubuntu —— opencv 学习笔记 （ 1 ）

$ sudo apt-get install build-essential

$ sudo apt-get install mesa-common-dev
$ sudo apt-get install libglu1-mesa-dev -y

#include "mainwindow.h"
#include <QApplication>
#include <QWidget>
#include <QLabel>
#include <QTextCodec>
#include <QPushButton>
#include <QVBoxLayout>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);

QWidget* pWidget = new QWidget;
QLabel label( pWidget );
label.setText(QObject::tr("----hello world!----"));
QPushButton* btn = new QPushButton( QObject::tr( "close" ), pWidget );

QVBoxLayout* layout = new QVBoxLayout;
layout->addWidget( &label );
layout->addWidget(btn);
pWidget->setLayout(layout);

QObject::connect( btn, SIGNAL( clicked(bool)), pWidget, SLOT( close() ) );

pWidget->show();
return a.exec();
}