title: QMessageBox disappears
body: <p>I'm trying to display a <code>QMessageBox</code> through calling its <code>show</code> function in a lambda function like the following:</p>
  
  <pre><code>connect(ui-&gt;graphButton, &amp;QAbstractButton::clicked, [](void){
          QMessageBox message;
          message.setText(tr("Graphing button clicked"));
          message.show();
  });
  </code></pre>
  
  <p>However, upon clicking the <code>graphButton</code>, the <code>QMessageBox</code> window appears only momentarily before disappearing. How can I fix this?</p>