title: Building a Qt example doen't give the same output, window customizing
body: <p>Can someone explain to me why when I build this example <a href="http://doc.qt.io/qt-5/qtwidgets-desktop-screenshot-example.html" rel="nofollow noreferrer">http://doc.qt.io/qt-5/qtwidgets-desktop-screenshot-example.html</a>, I don't get the same output as show in that example, instead I get the default windows window style.
  <a href="https://i.stack.imgur.com/foUxO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/foUxO.png" alt=""></a>
  left as in the example, right my output</p>
  
  <p>This leads to another question: </p>
  
  <p>if I want to customize my window using <code>Qt Widget Application</code> to something other than the default style/design, how is that possible?</p>
  
  <p>Ps: I already tried to fill the background with a color, it worked but didn't applied on the window borders.</p>