Qt (3) Check QtDesigner and the ui file

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QtGui>
 
#ifndef _DEBUG
#pragma comment(lib, "QtUiTools.lib")
#else
#pragma comment(lib, "QtUiToolsd.lib")
#endif
 
class MainWindow : public QWidget
{
	Q_OBJECT
 
public:
	MainWindow();
 
private slots:
    void on_pushButton_clicked();
 
};
#endif

#include "QMessageBox"
#include "mainwindow.h"
#include "QFile"
#include "QtUiTools/QUiLoader"
 
MainWindow::MainWindow()
{
	QUiLoader oloader;
 
	QFile ofile("test.ui");
	ofile.open(QFile::ReadOnly);
 
	QWidget *widget = oloader.load(&ofile, this);
	ofile.close();
 
	QPushButton* ui_findButton = qFindChild<QPushButton*>(widget, "pushButton");
 
	if(ui_findButton!=NULL){
		connect(ui_findButton, SIGNAL(clicked()), 
		        this, SLOT(on_pushButton_clicked()));
	} else {
		QMessageBox::information (NULL,"Nothing","Nothing pushButton.");
	}
 
    setWindowTitle(tr("SampleWindow"));
 
}
 
void MainWindow::on_pushButton_clicked()
{
	QMessageBox::information (NULL,"Click","Click Click!!");
}

#include <QApplication>
 
#include "mainwindow.h"
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MainWindow mainWin;
    mainWin.show();
    return app.exec();
}