Difficulty in Qlabel and POO

[Gutoficiall]

I'm having trouble updating the value of label_Number, which I defined in my interface (myDialog.ui)
When I click on MainWindow::on_pushButton_clicked, through my MainWindow.

MainWindow.h and .cpp:

void MainWindow::on_pushButton_clicked(){
    obj.setNumber(ui->lineEdit_Number->text().toInt());
    qDebug() << obj.getNumber();
    myDialog ptr; ptr.exec();
}

myDialog.h:

myDialog(Qwidget *parent) : QDialog(parent), ui(new Ui::myDialog){
	ui->setupUi(this);
	myClass obj;
	 ui->label_Number->setText(QString::number(obj.getNumber()));
}

In my case, I would have to create a Qlabel as private in my myDialog, and making a method to access
my ui->label_Number, being able to update the value directly from my MainWindow button, without having to create a button inside myDialog to refresh;

[JonB]

@Gutoficiall
To pass the number from MainWindow to myDialog, either create a parameter for it in the dialog constructor (if the number is only passed at construction time) or write a setter method in the dialog which accepts a number and sets its ui->label_Number from that. You do not need to export the QLabel from the dialog.

[Gutoficiall]

@JonB
Thank you take the weight off my back and help clarify, I've been thinking for hours. I was lost here...