C++ Qt5.11 error :" C2661: No overloaded function takes 3 arguments"

Question

I am new to Qt and when I tried to compile and run a Qt program from "Foundations of Qt Development " Chapter 7, see

http://www.java2s.com/Code/Cpp/Qt/QGraphicsViewQGraphicsItemandQGraphicsScene.htm

#include <QApplication>

#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsRectItem>
#include <QGLWidget>

QGraphicsItem *createItem( int x, QGraphicsScene *scene )
{
  QGraphicsRectItem *rectItem = new QGraphicsRectItem( QRect( x+40, 40, 120, 120 ), 0, scene );
  rectItem->setPen( QPen(Qt::black) );
  rectItem->setBrush( Qt::gray );

  QGraphicsRectItem *innerRectItem = new QGraphicsRectItem( QRect( x+50, 50, 45, 100 ), rectItem, scene );
  innerRectItem->setPen( QPen(Qt::black) );
  innerRectItem->setBrush( Qt::white );

  QGraphicsEllipseItem *ellipseItem = new QGraphicsEllipseItem( QRect( x+105, 50, 45, 100 ), rectItem, scene );
  ellipseItem->setPen( QPen(Qt::black) );
  ellipseItem->setBrush( Qt::white );

  return rectItem;
}

int main( int argc, char **argv )
{
  QApplication app( argc, argv );

  QGraphicsScene scene( QRect( 0, 00, 1000, 200 ) );

  QGraphicsItem *item1 = createItem( 0, &scene );

  QGraphicsItem *item2 = createItem( 200, &scene );
  item2->translate( 300, 100 );
  item2->rotate( 30 );
  item2->translate( -300, -100 );

  QGraphicsItem *item3 = createItem( 400, &scene );
  item3->translate( 500, 100 );
  item3->scale( 0.5, 0.7 );
  item3->translate( -500, -100 );

  QGraphicsItem *item4 = createItem( 600, &scene );
  item4->translate( 700, 100 );
  item4->shear( 0.1, 0.3 );
  item4->translate( -700, -100 );

  QGraphicsItem *item5 = createItem( 800, &scene );
  item5->translate( 900, 100 );
  item5->scale( 0.5, 0.7 );
  item5->rotate( 30 );
  item5->shear( 0.1, 0.3 );
  item5->translate( -900, -100 );

  QGraphicsView view;
  view.setScene( &scene );
  view.setViewport( new QGLWidget() );
  view.show();

  return app.exec();
}

I always got the error info " error: C2661: “QGraphicsRectItem::QGraphicsRectItem”: "No overloaded function takes 3 arguments".I tried again and again but all the same.Could somebody help me solving this problem? Thanks.

I am using Qt5.11.0 and MSVC2017 and Windows 10 pro X64.

You should bring the code here, and then ask the question specifically about the code. — arashka, Jul 22 '18 at 13:34
For the future, when referring to compiler errors -- you should indicate what line in your enclosed example they refer to. I.e. add a comment or an arrow pointing to where the error is. — Kuba hasn't forgotten Monica, Jul 22 '18 at 17:29

paxdiablo · Answer 1 · 2018-07-22T14:35:53.683

It means exactly what it says, that you are trying to call the constructor of QGraphicsRectItem with three arguments:

... = new QGraphicsRectItem(QRect(x+40, 40, 120, 120), 0, scene);
                            \______________________/   |  \___/
                                        1              2    3

If you look at the documentation, you'll see that no such constructor exists:

QGraphicsRectItem(QGraphicsItem *parent = nullptr);
QGraphicsRectItem(const QRectF &rect, QGraphicsItem *parent = nullptr)
QGraphicsRectItem(qreal x, qreal y, qreal width, qreal height, QGraphicsItem *parent = nullptr);

The first has one optional argument (so zero or one), the second has one mandatory and one optional (so one or two) and the third has four mandatory and one optional (so four or five).

If you examine that previous paragraph closely, you'll notice that one thing missing is the word "three" :-) I'd suggest ditching that tutorial since it's very old. Qt 4.2 (when that class was first introduced) did have a three-argument version which included the scene, but that was very short-lived and removed in 4.3.

For 5.11, further reading of the linked documentation shows up the fact that the (my emphasis):

QGraphicsRectItem class provides a rectangle item that you can add to a QGraphicsScene.

Hence the correct way to do what you appear to need is:

QGraphicsRectItem *rectItem = new QGraphicsRectItem(QRectF(x+40, 40, 120, 120));
scene->addItem(rectItem);

score 1 · Answer 2 · answered Jul 22 '18 at 14:17

The code you sample is inconsistent with Qt5, an updated translation is as follows:

#include <QApplication>

#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsRectItem>
#include <QOpenGLWidget>


static QGraphicsItem *createItem( int x, QGraphicsScene *scene )
{
    QGraphicsRectItem *rectItem = new QGraphicsRectItem(QRectF( x+40, 40, 120, 120 ));
    scene->addItem(rectItem);
    rectItem->setPen(QPen(Qt::black));
    rectItem->setBrush( Qt::gray );

    QGraphicsRectItem *innerRectItem = new QGraphicsRectItem( QRect( x+50, 50, 45, 100 ), rectItem);
    innerRectItem->setPen( QPen(Qt::black) );
    innerRectItem->setBrush( Qt::white );

    QGraphicsEllipseItem *ellipseItem = new QGraphicsEllipseItem( QRect( x+105, 50, 45, 100 ), rectItem);
    ellipseItem->setPen( QPen(Qt::black) );
    ellipseItem->setBrush( Qt::white );

    return rectItem;
}

int main( int argc, char **argv )
{
    QApplication app( argc, argv );

    QGraphicsScene scene( QRect( 0, 00, 1000, 200 ) );


    QGraphicsItem *item1 = createItem( 0, &scene );

    QGraphicsItem *item2 = createItem( 200, &scene );
    QTransform tr2;
    tr2.translate( 300, 100 );
    tr2.rotate( 30 );
    tr2.translate( -300, -100 );
    item2->setTransform(tr2);

    QGraphicsItem *item3 = createItem( 400, &scene );
    QTransform tr3;
    tr3.translate( 500, 100 );
    tr3.scale( 0.5, 0.7 );
    tr3.translate( -500, -100 );
    item3->setTransform(tr3);

    QGraphicsItem *item4 = createItem( 600, &scene );
    QTransform tr4;
    tr4.translate( 700, 100 );
    tr4.shear( 0.1, 0.3 );
    tr4.translate( -700, -100 );
    item4->setTransform(tr4);

    QGraphicsItem *item5 = createItem( 800, &scene );
    QTransform tr5;
    tr5.translate( 900, 100 );
    tr5.scale( 0.5, 0.7 );
    tr5.rotate( 30 );
    tr5.shear( 0.1, 0.3 );
    tr5.translate( -900, -100 );
    item5->setTransform(tr4);

    QGraphicsView view;
    view.setScene( &scene );
    view.setViewport( new QOpenGLWidget() );
    view.show();

    return app.exec();
}

*.pro

QT       += core gui widgets opengl

TEMPLATE = app
CONFIG += c++11

SOURCES += main.cpp

When writing `.pro` files, it helps to know that the dependencies are transitively included, and that adding to `QT` is not necessary: you have full control over what modules you want. So simply set it: `QT = widgets opengl`. The `core` and `gui` modules are included automatically. For Qt 5.7 and later, the `CONFIG += c++11` is unnecessary: Qt 5.7 required C++11 support and the code won't compile without it. `TEMPLATE = app` is the default, so you can skip that, too. You only need two lines: `QT=` and `SOURCES=` :) Thankfully, modern cmake isn't much worse either - it needs IIRC just 5 lines. — Kuba hasn't forgotten Monica, Jul 22 '18 at 17:34
@KubaOber I understand what you tell me, but even Qt Creator generates more unnecessary elements that I have eliminated, I think that placing a little more does not hurt :), I would do if my .pro was extensive, but it is not, I will take it in account for my next publications, thanks. :) — eyllanesc, Jul 22 '18 at 17:39

C++ Qt5.11 error :" C2661: No overloaded function takes 3 arguments"

2 Answers2