QLabel->setScaledContents() does not work

lincoln

Hello friends, I have the following code:

#include "dialog.h"
#include "ui_dialog.h"
#include <QMessageBox>
#include <QFileDialog>
Dialog::Dialog(QWidget *parent)
  : QDialog(parent)
  , ui(new Ui::Dialog)
{
  ui->setupUi(this);

}

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


void Dialog::on_toolButton_clicked()
{
  QString fileName=QFileDialog::getOpenFileName(this,"Abrir imagenes",
                                                QDir::rootPath(),"Imagenes (*.jpg *.jpeg *.png)");
  if(fileName.isEmpty())
    {
      return;
    }
  ui->label->setPixmap(QPixmap(fileName));
  ui->label->setScaledContents(true);

}

what I want is that when loading an image in the QLabel it adjusts to the size of the control but it doesn't work, I already put it in the constructor but it didn't work either; I tried to mark the property in the graphic designer but nothing, I would like to know why it is not working.

Christian Ehrlicher

#include <QtWidgets>
int main(int argc, char **argv)
{
    QApplication app(argc, argv);

    QString fileName=QFileDialog::getOpenFileName(nullptr, QString(), QString(), "Imagenes (*.jpg *.jpeg *.png)");
    QLabel lbl;
    lbl.setPixmap(QPixmap(fileName));
    lbl.setScaledContents(true);
    lbl.show();

    return app.exec();
}

This is working fine for me - an image set on the label is scaled and resized when I resize the label.

Kent-Dorfman

My guess is that it is because the OP is trying to modify the pixmap in a label managed from within a dialog. The dialog is probably setting some constraints that override the setScaledContent() call.