title: QGraphicsView Zooming in and out with qpushbutton
body: <p>I have a  <code>QGraphicsScene</code> and i want to do zooming ( in and out ) with a <code>qpushbutton</code> , i have this code : </p>
  
  <pre><code>void fonction(){
          Scene = new QGraphicsScene(this);
          ui-&gt;graphicsView-&gt;setScene(Scene);
          QPen Pen ;
          QBrush Brush(Qt::red) ;
          Pen.setWidth(5);
          ellipse = Scene-&gt;addEllipse(2,2,30,30,Pen,Brush);
  }
  </code></pre>
  
  <p>How to do it ? 
  I have tried : </p>
  
  <pre><code>void HomePage::on_pushButton_4_clicked()
  {
      if(Zoom!=10 ){
          Zoom=Zoom+0.1 ;
         }
      ui-&gt;graphicsView-&gt;show();
  
  }
  </code></pre>
  
  <p>But something does not happen .</p>