MainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "mycomparefiledialog.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    myDialog = new MyCompareFileDialog(this);

    connect(ui->pushButton,SIGNAL(clicked()),myDialog,SLOT(exec()));
}

MainWindow::~MainWindow()
{
    delete ui;
}