How to Send Data from One Ui to Another

[delivite]

Hi,

I have one MainWindow and one Class; I want to send data between them using custom signal and slot. I can't seem to figure it out, I need help.

Here is my code:
MainWindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <iostream>
#include "receive.h"
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
signals:
    void sendit(QString name);
private slots:
    void on_send_button_clicked();
    void display(QString e)
    {        
     std::cout<<"Here is where I am called this "<<e.toStdString()<<std::endl;
    }

private:
    Ui::MainWindow *ui;
   
};
#endif // MAINWINDOW_H

MainWindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "receive.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);    
   Receive *r = new Receive();
   connect(this, SIGNAL(sendit(QString)), r, SLOT(display(QString)));

}

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


void MainWindow::on_send_button_clicked()
{
    emit sendit(ui->lineEdit->text());

}

receive.h

#ifndef RECEIVE_H
#define RECEIVE_H

#include <iostream>
#include <QDialog>

class Receive : public QDialog
{
public:
    Receive();
private slots:
    void display(QString e);
};

#endif // RECEIVE_H

receive.cpp

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

Receive::Receive()
{
    
}

void Receive::display(QString e)
{    
 std::cout<<"Here is where I am called this "<<e.toStdString()<<std::endl;
}

When I run this program, I get this message:

06:26:29: Starting C:\Users\Troy\Documents\build-tests-Desktop_Qt_5_14_1_MinGW_32_bit-Debug\tests.exe ...
QObject::connect: No such slot QDialog::display(QString) in ..\tests\mainwindow.cpp:11
QObject::connect: (sender name: 'MainWindow')

How do I get this done, please?

Thank you for your help.

[jsulm]

@delivite Make your slot public, not private