Transfer Data Between Two Forms

[Sekhar]

This is my code:

send.h :

#ifndef SEND_H
#define SEND_H

#include <QMainWindow>

namespace Ui {
class send;
}

class send : public QMainWindow
{
    Q_OBJECT

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

private slots:
    void on_pushButton_clicked();
    void showReceiveForm();

signals:
    void newTextEntered(const QString &text);

private:
    Ui::send *ui;
};

#endif // SEND_H

send.cpp :

#include "send.h"
#include "ui_send.h"

#include "chaild.h"
#include "ui_chaild.h"

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

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

void send::on_pushButton_clicked()
{
   emit newTextEntered(ui->lineEdit->text());

    chaild ss;
    ss.show();
    ss.exec();
}

chaild.h :

#ifndef CHAILD_H
#define CHAILD_H

#include <QDialog>

namespace Ui {
class chaild;
}

class chaild : public QDialog
{
    Q_OBJECT

public:
    QString ss;
    explicit chaild(QWidget *parent = 0);
    ~chaild();

private slots:
    void on_spinBox_valueChanged(int arg1);

public slots:
    void onNewTextEntered(const QString &text);

private:
    Ui::chaild *ui;
};

chaild.cpp :

#include "chaild.h"
#include "ui_chaild.h"

#include "send.h"
#include "ui_send.h"

chaild::chaild(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::chaild)

{
    ui->setupUi(this);

    send st;

    connect(&st,SIGNAL(newTextEntered(QString)),this,SLOT(onNewTextEntered(QString)));
}

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

void chaild::on_spinBox_valueChanged(int age)
{
     ui->spinBox->setValue(age);
}

void chaild::onNewTextEntered(const QString &text)
{
    // Adding a new item to the list widget
    ui->textEdit->setText(text);
}

please tell me how to pass the data from send form to chaild form

[edit: koahnig, code tags introduced]

[koahnig]

@Sekhar

Hi and welcome to devnet forums

I would suggest to you to have a look to the different examples for instance this http://doc.qt.io/qt-5/qtwidgets-dialogs-standarddialogs-example.html

The problem you are generating is that these dialogs cross-dependencies.

send is derived from QMainWindow which would typically exist the whole time. However, you are generating a local copy in your constructor of chaild:

chaild::chaild(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::chaild)

{
    ui->setupUi(this);

    send st;

    connect(&st,SIGNAL(newTextEntered(QString)),this,SLOT(onNewTextEntered(QString)));
}

Basically the send object is deleted immediately after the connect statement since the local object gets out of focus.

in send you do it basically the other way around:

void send::on_pushButton_clicked()
{
   emit newTextEntered(ui->lineEdit->text());    // sending the signal with information 

    chaild ss;          // now you create the obejct where you expect to receive the signal
    ss.show();
    ss.exec();
}

You are sending a signal to something that does not yet exist.

I think best is with the example code given above, you can start doing modifications and therefore find out more about the different strategies. Also other examples might help you.

[elfring]

please tell me how to pass the data from send form to chaild form

• How do you think about to take a bit more data modelling and corresponding presentation aspects into account?
• Would you like to clarify the amount of desired data exchange at these places?