Why I see: Object::connect: No such slot QDialog::showName(QString) in

8Observer8

Hi,

Why I see: Object::connect: No such slot QDialog::showName(QString) in ../DialogByButton/mainwindow.cpp:29

DialogByButton.pro
[CODE]
SOURCES +=
main.cpp
mainwindow.cpp
dialog.cpp

HEADERS +=
mainwindow.h
dialog.h
[/CODE]

dialog.h
[CODE]
#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QtGui>

class Dialog : public QDialog
{
Q_OBJECT
public:
explicit Dialog(QWidget *parent = 0);

signals:

public slots:
void showName(QString name);

private:
QLabel *lblName;
};

#endif // DIALOG_H
[/CODE]

dialog.cpp
[CODE]
#include "dialog.h"

Dialog::Dialog(QWidget *parent) :
QDialog(parent)
{
// Controls
lblName = new QLabel(tr("Hahah"));

// Layouts
QHBoxLayout* mainLayout = new QHBoxLayout(this);
mainLayout->addWidget(lblName);

// Set Layout
this->setLayout(mainLayout);

}

void Dialog::showName(QString name) {
//lblName->setText(name);
}
[/CODE]

mainwindow.h
[CODE]
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtGui>

class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);

signals:
void sendName(QString name);

private slots:
void callDialog();

private:
QLineEdit *leName;
};

#endif // MAINWINDOW_H
[/CODE]

mainwindow.cpp
[CODE]
#include "mainwindow.h"
#include "dialog.h"
#include <QWidget>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent)
{
// Controls
QLabel *lblName = new QLabel(tr("Enter your name:"));
leName = new QLineEdit;
QPushButton *btnCallDialog = new QPushButton(tr("Call Dialog"));

// Layout
QGridLayout *mainLayout = new QGridLayout;
mainLayout->addWidget(lblName, 0, 0);
mainLayout->addWidget(leName, 0, 1);
mainLayout->addWidget(btnCallDialog, 1, 0, 1, 2);

// Set center widget
QWidget *widget = new QWidget;
widget->setLayout(mainLayout);
this->setCentralWidget(widget);

connect(btnCallDialog, SIGNAL(clicked()), this, SLOT(callDialog()));

}

void MainWindow::callDialog() {
QDialog *dialog = new QDialog(this);
connect(this, SIGNAL(sendName(QString)), dialog, SLOT(showName(QString)));
emit sendName(leName->text());
dialog->show();
}
[/CODE]

main.cpp
[CODE]
#include <QApplication>
#include "mainwindow.h"

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

MainWindow window;
window.show();

return app.exec();

}
[/CODE]

Thank you!

p3c0

Hi,

Because you are creating Object of QDialog and it doesnot have Slot showName(QString). It should be Dialog which is your class and it contains showName(QString).

raven-worx

because - as the error message says - the QDialog class doesn't have such a slot.
@
QDialog *dialog = new QDialog(this);
connect(this, SIGNAL(sendName(QString)), dialog, SLOT(showName(QString)));
@

You should rather create a instance of your class ("Dialog") where you defined this slot rather than QDialog.

8Observer8

Thank you very much.

I write instead:
[CODE]
void MainWindow::callDialog() {
QDialog *dialog = new QDialog(this);
connect(this, SIGNAL(sendName(QString)), dialog, SLOT(showName(QString)));
emit sendName(leName->text());
dialog->show();
}[/CODE]

This code:
[CODE]
void MainWindow::callDialog() {
Dialog dialog;
connect(this, SIGNAL(sendName(QString)), &dialog, SLOT(showName(QString)));
emit sendName(leName->text());
dialog.exec();
}}[/CODE]

SGaist

Hi,

With the last version of your code, there is no need for the connection just use:

@dialog.showName(leName->text());@

8Observer8

You are right. I see. Thanks!