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 <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();}