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

1、从Qt官网下载集成开发环境并运行
http://download.qt-project.org/official_releases/qt/5.4/5.4.0/qt-opensource-linux-x86-5.4.0.run
2、安装g++

$ sudo apt-get install build-essential

3、安装opengl lib

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

4、hello world
打开qt creater，新建Qt widgets application
main.cpp

#include "mainwindow.h"
#include 
#include 
#include 
#include 
#include 
#include 

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();
}