title: QT QPushButton Press Event
body: <p>i want to do a very time-consuming operation when press a QT button but failed, can anybody help me explain this? thanks!
  the code is:</p>
  
  <pre><code>bool eventFilter(QObject *target, QEvent *event)
  {
      if (target == ui.zoominBtn){
           if (event-&gt;type() == QEvent::MouseButtonPress){
               phcs[curPhcId].zoom(0.1);
               renderRaytracingImage();
           }
      }
      return QMainWindow::eventFilter(target, event);
  }
  </code></pre>
  
  <p>now i move the time consuming-part to a QThread:</p>
  
  <pre><code>if (target == ui.zoominBtn){
      if (event-&gt;type() == QEvent::MouseButtonPress){
          //phcs[curPhcId].zoom(0.1);
          TracerayThread *traceThread = new TracerayThread(&amp;scene,&amp;(phcs[curPhcId]),this);
          connect(traceThread, SIGNAL(resultReady()), this, SLOT(render()));
          connect(traceThread, SIGNAL(finished()), traceThread, SLOT(deleteLater()));
          traceThread-&gt;start();
      }
  }
  </code></pre>
  
  <p>i need to pass two pointer to the new thread,can i do this? </p>