QSlider & QLabel : setText after SIGNAL from QSlider not working

[Faradn]

Hi,

As the title states, I have some issues with a QSlider/QLabel connection.

I simply want to show the slider's position in a label as a text and update it every time the slider is changed (and all this in a QMessageBox).

Here's the failing code :

/* In the mainFrame constructor ... */
 
  delete choiceBoxB.layout();
  choiceBoxBLayout = new QVBoxLayout;
  choiceBoxB.setLayout(choiceBoxBLayout);
  sliderPosB = new QLabel("100%");
  percentageSliderB = new QSlider(Qt::Horizontal);
  percentageSliderB->setMinimum(0);
  percentageSliderB->setMaximum(200);
  percentageSliderB->setSliderPosition(100);
  connect(percentageSliderB,SIGNAL(valueChanged(int)),this,SLOT(updateSliderBPos(int)));
  choiceBoxBLayout->addWidget(sliderPosB);
  choiceBoxBLayout->addWidget(percentageSliderB);
 
/* ... */
 
void mainFrame::updateSliderBPos(int value){
  sliderPosB->setText(QString("%1%").arg(value));
}

/* In the mainFrame constructor ... */

  delete choiceBoxB.layout();
  choiceBoxBLayout = new QVBoxLayout;
  choiceBoxB.setLayout(choiceBoxBLayout);
  sliderPosB = new QLabel("100%");
  percentageSliderB = new QSlider(Qt::Horizontal);
  percentageSliderB->setMinimum(0);
  percentageSliderB->setMaximum(200);
  percentageSliderB->setSliderPosition(100);
  connect(percentageSliderB,SIGNAL(valueChanged(int)),this,SLOT(updateSliderBPos(int)));
  choiceBoxBLayout->addWidget(sliderPosB);
  choiceBoxBLayout->addWidget(percentageSliderB);

/* ... */

void mainFrame::updateSliderBPos(int value){
  sliderPosB->setText(QString("%1%").arg(value));
}

To copy to clipboard, switch view to plain text mode 

Every variable or object or class has been declared in the header file (no compiling issues).

For some reason I don't understand, it worked almost fine once but I couldn't find out what was not working, that wasn't enough.

The purpose of the slider and the label is to allow user to choose a percentage to change the brightness of an image (project in an image editor).

Thanks for your help,

Faradn

UPDATE :

I forgot to mention that the input text is perfectly fine (tested with std::cout) and that the signal works fine too. It is the setText that is not working properly.