title: QR code reader for Windows Phone
body: <p>I'm working on a Windows Phone app and I need a simple QR code reader. I'm following <a href="http://blogs.msdn.com/b/richmac/archive/2011/11/07/creating-a-qr-code-reader-app-for-windows-phone-7.aspx" rel="nofollow">a tutorial</a>. </p>
  
  <p>I did everything, and now I must add </p>
  
  <pre><code>private PhotoCamera camera;
  </code></pre>
  
  <p>But there is always this error: </p>
  
  <pre><code>The type or namespace name 'PhotoCamera' could not be found (are you missing a using directive or an assembly reference?)
  </code></pre>
  
  <p>Why am I getting this error?</p>