How to resize a Qwidget to bigger than default size

Question

I have a problem with the size of widget in Qt. I am Using it to display some game pictures, but it doesn't fit in there, it just adds two scrollbars, which is not what I need.

I tried this:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    this->maze = new MazeGUI();

    QHBoxLayout * layout = new QHBoxLayout;
    layout->addWidget(this->maze);
    ui->widget->setLayout(layout);
    ui->widget->resize(800, 600);
}

It works when I use "ui->widget->resize(200, 200);" which is smaller than some default size. But when I try some bigger number like in example, it doesn't work, just sets the QWidget size to the default size.

Edit: Maybe this will help solving the problem.

   <widget class="QWidget" name="widget" native="true">
    <property name="geometry">
     <rect>
      <x>50</x>
      <y>10</y>
      <width>511</width>
      <height>361</height>
     </rect>
    </property>
    <property name="sizePolicy">
     <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
      <horstretch>0</horstretch>
      <verstretch>0</verstretch>
     </sizepolicy>
    </property>
   </widget>

Answer 1

You may have to set minimum width/height before resizing. Check this link.