How to Call .ui Design Form with The PushButton.clicked event in Qt C++ with Example?

1. Create a new Qt GUI Application project.
2. Right Click the Forms folder in the current project, then choose “Add New...”.
3. Choose the Qt Designer Form Class
4. Choose the window template
5. Name the form and locate the folder where it will be saved
6. Finish.
7. Now do the rest:

main.cpp:
#include <QtGui/QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}



mainwindow.h:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

#include <aboutme.h> //add the include .h file of your form

namespace Ui {
    class MainWindow;
}

class MainWindow : public QMainWindow {
    Q_OBJECT
public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
public slots:
    void openAbout(); //make a new function to call the window

protected:
    void changeEvent(QEvent *e);

private:
    Ui::MainWindow *ui;
    AboutMe     *winAbout; //make a new declaration for the new window


private slots:
    void on_pushButton_2_clicked();
    void on_pushButton_clicked();
};

#endif // MAINWINDOW_H


mainwindow.cpp:
#include "mainwindow.h"
#include "ui_mainwindow.h"

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

MainWindow::~MainWindow()
{
    delete ui;
}
void MainWindow::openAbout()
{
    winAbout = new AboutMe(this);
    winAbout->show();
}

void MainWindow::changeEvent(QEvent *e)
{
    QMainWindow::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}

void MainWindow::on_pushButton_clicked()
{
    openAbout();
}

void MainWindow::on_pushButton_2_clicked()
{
    exit(1);
}


aboutme.h:
#ifndef ABOUTME_H
#define ABOUTME_H

#include <QMainWindow>

namespace Ui {
    class AboutMe;
}

class AboutMe : public QMainWindow {
    Q_OBJECT
public:
    AboutMe(QWidget *parent = 0);
    ~AboutMe();

protected:
    void changeEvent(QEvent *e);

private:
    Ui::AboutMe *ui;

private slots:
    void on_pushButton_clicked();
};

#endif // ABOUTME_H

aboutme.cpp:
#include "aboutme.h"
#include "ui_aboutme.h"

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

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

void AboutMe::changeEvent(QEvent *e)
{
    QMainWindow::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}

void AboutMe::on_pushButton_clicked()
{
    close();
}

DOWNLOAD THE PROJECT (.zip)