Connecting textEdit with label

[ejoty]

I tried to connect a textEdit to a label on a different page using stackedWidget, so that when a text is written in textEdit the same text is shown in the label on the next page, but so far it didnt work out. My textEdits Name is "textEdit_name" and my labels Name is "label_name". My Code so far is

void Volk_Auswahl::label_name()
{
  connect(ui->textEdit_name, SIGNAL(textChanged()), this, SLOT(label_name()));
}

void Volk_Auswahl::label_name()
{
  connect(ui->textEdit_name, SIGNAL(textChanged()), this, SLOT(label_name()));
}

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There is no error but when I type something in textEdit there is no text in label.

[Lesiok]

And what is doing slot label_name() ?

[ejoty]

I dont know which funtion to use. Sry I am new at this.

[d_stranz]

Showing 4 lines of code is not going to help us understand how to help you with your problem.

If this is basically the same problem as your other post, then please don't post the same question twice.

So I assume you have two QWidget-based classes that are the two widgets you have created for your two stack widget pages. One of these has a QTextEdit (or a QLineEdit - which you should be using if all you want is for the user to be able to enter a short string, like a name) and the other widget has a QLabel. You want the QLabel to display the same text that the user types into the QTextEdit or QLineEdit, right?

The code you posted above makes no sense at all, or maybe you don't really understand signals and slots. The connect() statement is basically saying, "When the first widget emits this signal, I want you to send it to this slot of the second widget". It prepares the two widgets for something that will happen at some time in the future. It is not an instruction to do something now. So putting a connect() statement inside a slot doesn't cause anything to happen (except add another connection each time that slot is called - probably not what you want).

The correct procedure, and one that creates an abstraction so that the widget on stack position 0 doesn't have to know anything about the contents of the widget on stack position 1 is to implement a signal and slot pair that can relay the signal from the QTextEdit / QLineEdit to the QLabel, through their parent widgets.

Something like this. Don't copy and paste this code. Study it and understand what it is doing.

// Widget0 is the QWidget that contains the QTextEdit
class Widget0 : public QWidget
{
	Q_OBJECT;
 
public:
	Widget0( QWidget * parent = nullptr );
 
	// ...
signals:
	void nameChanged( const QString & name );
 
private slots:
	void onTextChanged();
 
private:
	Widget0::Ui	ui;  // Contains the QTextEdit or QLineEdit
};
 
// In the constructor, set up a signal slot connection so the QTextEdit can tell Widget0
// when its contents have changed
Widget0::Widget0( QWidget * parent )
	: QWidget( parent )
{
	ui.setupUi( this );
 
	connect( ui.textEdit, SIGNAL( textChanged() ), this, SLOT( onTextChanged() ) );
}
 
// Slot implementation.  When the text has changed, this will be called.
// In it, we get the contents of the QTextEdit as an ordinary string,
// then emit our signal so the rest of the world can be notified
void Widget0::onTextChanged()
{
	QString text = ui->textEdit->toPlainText();
	emit nameChanged( text );
}
 
// Widget1 is the QWidget that contains the QLabel
class Widget1 : public QWidget
{
	Q_OBJECT;
 
public:
	Widget1( QWidget * parent = nullptr );
	// ...
 
public slots:
	void onNameChanged( const QString & name );
 
private:
	Widget1::Ui	ui;		// contains the QLabel
};
 
Widget1::Widget1( QWidget * parent )
	: QWidget( parent )
{
	ui.setupUi( this );
}
 
// Slot.  Sets the label text
void Widget1::onNameChanged( const QString & name )
{
	ui.label_name->setText( name );
}
 
 
// In your MainWindow constructor is where you connect Widget0 and Widget1
// together
 
MainWindow::MainWindow( QWidget * parent )
	: QMainWindow( parent )
{
	ui.setupUi( this );
 
	// The magic part.  Now the QTextEdit's signal gets relayed through Widget0
	// to the slot in Widget1, which sets the label text.
	connect( ui.widget0, SIGNAL( nameChanged( const QString & ) ), ui.widget1, SLOT( onNameChanged( const QString & ) ) );
}

// Widget0 is the QWidget that contains the QTextEdit
class Widget0 : public QWidget
{
	Q_OBJECT;
	
public:
	Widget0( QWidget * parent = nullptr );
	
	// ...
signals:
	void nameChanged( const QString & name );
	
private slots:
	void onTextChanged();
	
private:
	Widget0::Ui	ui;  // Contains the QTextEdit or QLineEdit
};

// In the constructor, set up a signal slot connection so the QTextEdit can tell Widget0
// when its contents have changed
Widget0::Widget0( QWidget * parent )
	: QWidget( parent )
{
	ui.setupUi( this );
	
	connect( ui.textEdit, SIGNAL( textChanged() ), this, SLOT( onTextChanged() ) );
}

// Slot implementation.  When the text has changed, this will be called.
// In it, we get the contents of the QTextEdit as an ordinary string,
// then emit our signal so the rest of the world can be notified
void Widget0::onTextChanged()
{
	QString text = ui->textEdit->toPlainText();
	emit nameChanged( text );
}

// Widget1 is the QWidget that contains the QLabel
class Widget1 : public QWidget
{
	Q_OBJECT;
	
public:
	Widget1( QWidget * parent = nullptr );
	// ...
	 
public slots:
	void onNameChanged( const QString & name );
	
private:
	Widget1::Ui	ui;		// contains the QLabel
};

Widget1::Widget1( QWidget * parent )
	: QWidget( parent )
{
	ui.setupUi( this );
}

// Slot.  Sets the label text
void Widget1::onNameChanged( const QString & name )
{
	ui.label_name->setText( name );
}


// In your MainWindow constructor is where you connect Widget0 and Widget1
// together

MainWindow::MainWindow( QWidget * parent )
	: QMainWindow( parent )
{
	ui.setupUi( this );

	// The magic part.  Now the QTextEdit's signal gets relayed through Widget0
	// to the slot in Widget1, which sets the label text.
	connect( ui.widget0, SIGNAL( nameChanged( const QString & ) ), ui.widget1, SLOT( onNameChanged( const QString & ) ) );
}

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