c++ - Accessing methods of a subclassed QGraphicsRectItem object -

i have subclassed qgraphicsrectitem, named resizablerectitem. have added new member (int index), , 2 methods (getindex() , setindex() ). i'm adding resizablerectitems qgraphicsscene

resizablerectitem* item1 = new resizablerectitem(selrect.normalized()); scene()->additem(item1); 

later have call getindex() method, access items on items() of scene(), but

int idx = scene()->items().at(0)->getindex(); 

is incorrect, because scene()->items() qgraphicsitem , don't have getindex() method. correct solution ? thanks!

what correct solution?

if can re-think logic in code don't have depend on interface of resizablerectitem, best.

if cannot that, then, you'll need use dynamic_cast.

qgraphicsrectitem* gitem = scene()->items().at(0); resizablerectitem* item = dynamic_cast<resizablerectitem*>(gitem); if ( item != nullptr ) {    int idx = item->getindex(); }