Here the source codes :

setting scene with view :

Qt Code: 
  1. void View::setVisualModel(QGraphicsScene * model)
  2. {
  3.     qDebug () << this->visualClustersView->rect();
  4.     qDebug () << this->visualClustersView->sceneRect();
  5.     this->visualClustersView->setScene(model);
  6.     this->visualClustersView->setSceneRect(this->visualClustersView->rect);
  7.     qDebug () << this->visualClustersView->rect();
  8.     qDebug () << this->visualClustersView->sceneRect();
  9. }
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output :
QRect(0,0 640x480)
QRectF(0,0 0x0)
QRect(0,0 640x480)
QRectF(0,0 640x480)
but real view size is not 640x480.

Source code , what setting the items on scene :

Qt Code: 
  1. void Model::calculateNewVisualResult(QStandardItemModel *model)
  2. {
  3.     graphicsItems.clear();
  4.     this->visualResultModel->clear();
  5.     static QFont font("Times",9);
  6.     static QFontMetrics fn (font);
  7.     static int x =  0;
  8.     int y= 0;
  9.     static int yGrow = fn.height() -2;
  10.     static int maxSize =0;
  11.     this->graphicsItems.push_back(this->visualResultModel->addText(model->horizontalHeaderItem(0)->text(),font));
  12.     graphicsItems[0]->setPos(x,y);
  13.     maxSize = fn.width(graphicsItems.at(0)->toPlainText());
  14.     for(int i=1;i<model->rowCount();++i)
  15.     {
  16.         graphicsItems.push_back(visualResultModel->addText(model->horizontalHeaderItem(i)->text(),font));
  17.         graphicsItems[i]->setPos(x,y+yGrow);
  18.         y=graphicsItems.at(i)->pos().y();
  19.         if (maxSize < fn.width(graphicsItems.at(i)->toPlainText()))
  20.              maxSize = fn.width(graphicsItems.at(i)->toPlainText());
  21.     }
  22. emit this->visualModelCalculated(maxSize);
  23. }
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Becouse of fixed view size, my interface resizing to view size,and this looks ugly.
Where is my problem?