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?