title: BeagleBoard x15 shows only the last counter number? Qt
body: <p>I use BeagleBoard x15 to show a counter. When I click a button, it will run a loop:</p>
  
  <pre><code>for(int i=0;i&lt;10;i++){
      ui-&gt;label-&gt;setText(QString::number(i));
      delay(1s);
  }
  </code></pre>
  
  <p>But it only showed the last number: '9' on label. It should show: 1, 2, 3, 4, 5,...9 after each 1s. I use Qt. </p>
  
  <p>Can you tell me what happen? Thank you.</p>