Solving some errors.

[srohit24]

I have made all the changes you told me to, still the prob exists.

No link between pushButton and label.

#ifndef DIALOG_H
#define DIALOG_H
 
#include <QDialog>
 
 class QLabel;
 class QPushButton;
 
 namespace Ui
{
    class DialogClass;
}
 class Dialog : public QDialog
 {
     Q_OBJECT
 
 public:
     Dialog(QWidget *parent = 0);
     ~Dialog();
 
public slots:
    void myFunction1();
 
 private:
     QLabel *disLabel;
     QPushButton *pushButton;
     Ui::DialogClass *ui;
 };
 
#endif // DIALOG_H

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

 class QLabel;
 class QPushButton;

 namespace Ui
{
    class DialogClass;
}
 class Dialog : public QDialog
 {
     Q_OBJECT

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

public slots:
    void myFunction1();

 private:
     QLabel *disLabel;
     QPushButton *pushButton;
     Ui::DialogClass *ui;
 };

#endif // DIALOG_H

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#include "dialog.h"
#include "ui_dialog.h"
#include <QLibrary>
#include <QtGui>
 
 
 
 
 Dialog::Dialog(QWidget *parent)
     : QDialog(parent) ,ui(new Ui::DialogClass)
{
 
ui->setupUi(this);
disLabel = new QLabel;
 
pushButton = new QPushButton(tr("Sync"));
pushButton->setDefault(true);
 
connect(pushButton, SIGNAL(clicked()), this, SLOT(myFunction1()));
 
setWindowTitle(tr("Desktop Uploader"));
}
 
 
void Dialog::myFunction1()
{
    QLibrary myLib("dllprog");
    typedef char* (*MyPrototype)();
    MyPrototype myFunction = (MyPrototype) QLibrary::resolve("dllprog", "TestDll");
    char *b = myFunction();
    disLabel->setText(tr(b));
}
 
Dialog::~Dialog()
{
    delete ui;
}

#include "dialog.h"
#include "ui_dialog.h"
#include <QLibrary>
#include <QtGui>




 Dialog::Dialog(QWidget *parent)
     : QDialog(parent) ,ui(new Ui::DialogClass)
{

ui->setupUi(this);
disLabel = new QLabel;

pushButton = new QPushButton(tr("Sync"));
pushButton->setDefault(true);

connect(pushButton, SIGNAL(clicked()), this, SLOT(myFunction1()));

setWindowTitle(tr("Desktop Uploader"));
}


void Dialog::myFunction1()
{
    QLibrary myLib("dllprog");
    typedef char* (*MyPrototype)();
    MyPrototype myFunction = (MyPrototype) QLibrary::resolve("dllprog", "TestDll");
    char *b = myFunction();
    disLabel->setText(tr(b));
}

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

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#include <QtGui/QApplication>
#include "dialog.h"
 
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Dialog dialog;
     dialog.show();
     return dialog.exec();
 }

#include <QtGui/QApplication>
#include "dialog.h"

 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Dialog dialog;
     dialog.show();
     return dialog.exec();
 }

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[spirit]

I would change this code

int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Dialog dialog;
     dialog.show();
     return dialog.exec();
 }

int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Dialog dialog;
     dialog.show();
     return dialog.exec();
 }

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to that

int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Dialog dialog;
     dialog.show();
     return app.exec();
 }

int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     Dialog dialog;
     dialog.show();
     return app.exec();
 }

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make next things: make clean & qmake & make.

[srohit24]

thanks mate.

Can you explain y i shoulf use app.exec();
rather than dialog.exec?

[srohit24]

connect(pushButton, SIGNAL(clicked()), this, SLOT(myFunction1()));

disLabel->setText(tr("b"));

I am returning a char b in the myFunction1() to check is the connection is working. When irun the app, same prob. no linking.

where is the mistake?

[spirit]

thanks mate.

Can you explain y i shoulf use app.exec();
rather than dialog.exec?

when you use app.exec that means that application event loop is started, but in you code when you use dialog.exec means that a dialog event loop is started.

so, if you want to create an another widget in you dialog and if you close your dialog (after closing event loop will be terminated) that widget which you created will be closed too, but if you use app.exec() that doesn't happen, becuse you don't terminate event loop.

[spirit]

what kind of error do you get?

[srohit24]

what kind of error do you get?

I am not getting any errors.

The app is not able to link the button and label in the designer with the actual code in the dialog.cpp.

QGridLayout *layout = new QGridLayout;
     layout->setColumnStretch(1, 1);
     layout->setColumnMinimumWidth(1, 1);
     layout->addWidget(syncButton, 0, 0);
     layout->addWidget(disLabel, 0, 1);
     setLayout(layout);
 
setWindowTitle(tr("Desktop Uploader"));
}

QGridLayout *layout = new QGridLayout;
     layout->setColumnStretch(1, 1);
     layout->setColumnMinimumWidth(1, 1);
     layout->addWidget(syncButton, 0, 0);
     layout->addWidget(disLabel, 0, 1);
     setLayout(layout);

setWindowTitle(tr("Desktop Uploader"));
}

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I had to write this code explicitly so that the label and the button are linked and it shows the desired result.

how can I solve that?

[spirit]

why you don't add these controls (a button and a label) in ui-file in Qt Disigner?

[srohit24]

I had, but there was no connection between them

How do i link them to the code?

[spirit]

to all controls you can get access using ui->.
so, you code should look like

...
connect(ui->pushButton, SIGNAL(clicked()), this, SLOT(myFunction1()));
...

...
connect(ui->pushButton, SIGNAL(clicked()), this, SLOT(myFunction1()));
...

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that's all.
now you can remove a lable and a pushbutton from class declaration.

[srohit24]

thanks a lot mate. it fixed my problem.

[srohit24]

How can i get the input from the users??

i have used this code

void Dialog::gettext()
{
QString text = QInputDialog::getText(this, tr("Enter the username"),
                                          tr("User name:"), QLineEdit::Normal);
     ui->dislabel->setText(text);
}

void Dialog::gettext()
{
QString text = QInputDialog::getText(this, tr("Enter the username"),
                                          tr("User name:"), QLineEdit::Normal);
     ui->dislabel->setText(text);
}

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but this code pops up a dialog which i dont need.

What i want is, when i add the text in the lineedit, it should be reflected in the label, or

when i add the text in the lineedit, a variable names text has to store it.

[spirit]

so, you need to add QLineEdit to your form and then

...
connect(ui->lineEdit, SIGNAL(textEdited(const QString &)), ui->label, SLOT(setText(const QString &)));
...

...
connect(ui->lineEdit, SIGNAL(textEdited(const QString &)), ui->label, SLOT(setText(const QString &)));
...

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this code will add a text from lineEdit to label.

...
connect(ui->pushButton, SIGNAL(clicked()), SLOT(getLineEditText()));//get text by clicking on a button
connect(ui->lineEdit, SIGNAL(editingFinished()), SLOT(getLineEditText()));//get text by pressing enter in a lineEdit
//you can also use QLineEdit::returnPressed insted of QLineEdit::editingFinished
...
 
void MyWidget::getLineEditText()
{
     qDebug() << ui->lineEdit->text();
}

...
connect(ui->pushButton, SIGNAL(clicked()), SLOT(getLineEditText()));//get text by clicking on a button
connect(ui->lineEdit, SIGNAL(editingFinished()), SLOT(getLineEditText()));//get text by pressing enter in a lineEdit
//you can also use QLineEdit::returnPressed insted of QLineEdit::editingFinished
...

void MyWidget::getLineEditText()
{
     qDebug() << ui->lineEdit->text();
}

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