How to made QGraphicsView fullscreen? - c++

Question

I have a QDialog window of size 800x480 and my sample image also have same size (800x480), But when it put it in QGraphicsView it showing a small space between image and window, how to avoid this space (yellow color )
I am using Qt5 in windows10
My code is
#include "dialog.h"
#include "ui_dialog.h"
Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
scene= new QGraphicsScene(this);
QPixmap pix(qApp->applicationDirPath()+QDir::separator()+"testImage.png");
pixItem = scene->addPixmap(pix);
ui->graphicsView->setScene(scene);
ui->graphicsView->showMaximized();
}
Dialog::~Dialog()
{
delete ui;
}
void Dialog::showEvent(QShowEvent *)
{
ui->graphicsView->fitInView(scene->sceneRect(), Qt::IgnoreAspectRatio);
}
And my xml generated by qt designer is
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>Dialog</class>
<widget class="QDialog" name="Dialog">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>800</width>
<height>480</height>
</rect>
</property>
<property name="windowTitle">
<string>Dialog</string>
</property>
<property name="styleSheet">
<string notr="true">background-color: rgb(255, 255, 0);</string>
</property>
<layout class="QGridLayout" name="gridLayout">
<property name="sizeConstraint">
<enum>QLayout::SetMaximumSize</enum>
</property>
<property name="leftMargin">
<number>0</number>
</property>
<property name="topMargin">
<number>0</number>
</property>
<property name="rightMargin">
<number>0</number>
</property>
<property name="bottomMargin">
<number>0</number>
</property>
<property name="spacing">
<number>0</number>
</property>
<item row="0" column="0">
<widget class="QGraphicsView" name="graphicsView">
<property name="sizePolicy">
<sizepolicy hsizetype="MinimumExpanding" vsizetype="MinimumExpanding">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
</property>
<property name="autoFillBackground">
<bool>false</bool>
</property>
<property name="frameShadow">
<enum>QFrame::Sunken</enum>
</property>
<property name="sizeAdjustPolicy">
<enum>QAbstractScrollArea::AdjustIgnored</enum>
</property>
</widget>
</item>
</layout>
</widget>
<resources/>
<connections/>
</ui>
I tried by adding image size bigger than 800x480 but the space is there

Answer 1

I used both QDialog and QMainwindow, but both of them have same problem with QGrapgicsView.
Finally I changed QGraphicsView with QLabel and it does not have this problem.