title: how to integrate qml file into qt-widgets app?
body: <p>I have an qt widgets application. I want to add the switch control to my form.
  I added to my form QDeclarative widget and add this line to the code but nothing shown.</p>
  
  <pre><code>ui-&gt;declarativeView-&gt;setSource(QUrl::fromLocalFile("test.qml"));
  </code></pre>
  
  <p>This is the content of the qml file (I added this file to the resources)
  It display in qtcreator under resources/[project_name.qrc]/test.qml</p>
  
  <pre><code>import QtQuick 2.4
  import QtQuick.Controls 1.3
  Button{
    text:aaaa
  }
  </code></pre>
  
  <p>I added the pro file : qt += declarative</p>
  
  <p>What am i doing wrong??</p>
  
  <p>I'm using Qt 5.4.1 QtCreator 3.3.1.</p>