How to call function which is in mainwindow.cpp from dailog.cpp in QT ?

[TM9412]

How to call function which is in mainwindow.cpp from dailog.cpp in QT ?

[J.Hilk]

@TM9412
hi, this is QT 101

//in your mainwindow

connect(PointerToDialogObject, &Dialog::mySignal, this, &MainWindow::mySlot);

[TM9412]

can you please provide more detail

I want to call the function from dailog.cpp file and that function which is in mainwindow.cpp file

[J.Hilk]

@TM9412

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

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    MainWindow mainw;
    mainw.show();

    return a.exec();
}

//mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>

class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = nullptr);


public slots:
    void okClicked();
    void CancleClicked();
};

#endif // MAINWINDOW_H

//Mainwindow.cpp
#include "mainwindow.h"
#include <QDebug>

#include "dialog.h"

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
    Dialog *dia = new Dialog();
    dia->show();

    connect(dia, &Dialog::btnOkClicked, this, &MainWindow::okClicked);
    connect(dia, &Dialog::btnCancelClicked, this, &MainWindow::CancleClicked);

    connect(dia, &Dialog::btnOkClicked, dia, &Dialog::deleteLater);
    connect(dia, &Dialog::btnCancelClicked, dia, &MainWindow::deleteLater);
}

void MainWindow::okClicked()
{
    qDebug() << "MainWindow" << "ok clicked in Dialog";
}

void MainWindow::CancleClicked()
{
    qDebug() << "MainWindow" << "Cancle clicked in Dialog";
}


//Dialog.h
#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();


signals:
    void btnOkClicked();
    void btnCancelClicked();
};

#endif // DIALOG_H


//Dialog.cpp
#include "dialog.h"
#include "QVBoxLayout"
#include "QPushButton"

Dialog::Dialog(QWidget *parent) :
    QDialog(parent)
{

    QPushButton *btnOk = new QPushButton("Ok");
    QPushButton *btnCancel = new QPushButton("Cancel");

    QVBoxLayout * layout = new QVBoxLayout();
    layout->addWidget(btnOk);
    layout->addWidget(btnCancel);
    this->setLayout(layout);

    connect(btnOk, &QPushButton::clicked, this, &Dialog::btnOkClicked);
    connect(btnCancel, &QPushButton::clicked, this, &Dialog::btnCancelClicked);
}

Dialog::~Dialog()
{
}

[TM9412]

thanks it is working..!

[TM9412]

HEY @J-Hilk

this code is working in my QT creator and a). and b). both scenario is working.
but when i was integrated this code in my existing application at that time i was observed the two result

a). Whenever my mainwindow is hidden and i pressed (clicked ) on the button my application is able to generate signal
and in the mainwindow that function was executing (calling) i.e. qDebug() << "MainWindow" << "ok clicked in Dialog";

b).
but i have both window together mainwindow and dialog in my application at that time button is not working i (clicked ) pressed the button not able to generate signal and not able to calling the maiwindow function. i.e same
qDebug() << "MainWindow" << "ok clicked in Dialog";

May be i was facing some focus issue in my application ??

[J.Hilk]

@TM9412 very hard to tell without some code to look at,
but you can investigate further on your own.

Either set a breakpoint in your Dialog.cpp to see if the clicked Signal is emitted, or connect a qDebug() output inside the Dialog.cpp and see if theres any output.