title: How to solve "error LNK2001: unresolved external symbol _CLSID_D2D1Blend" when using Direct2d Effects?
body: <p>I'm developing a Windows Runtime Component (Visual C++) drawing lib to be used on a Windows Store App C# Project.</p>
  
  <p>Everything was running as expected until I started to add some Effects capabilities to the lib.</p>
  
  <p>When trying to create an effect like bellow:</p>
  
  <pre><code>    m_d2dContext-&gt;CreateEffect(CLSID_D2D1Blend, &amp;m_blendEffect)
  </code></pre>
  
  <p>The following error is shown:</p>
  
  <pre><code>    1&gt;MyLibFile.obj : error LNK2001: unresolved external symbol _CLSID_D2D1Blend
  </code></pre>
  
  <p>I already have these pragma comments on my <code>pch.h</code>:</p>
  
  <pre><code>    #pragma comment(lib, "d3d11")
      #pragma comment(lib, "d2d1")
  </code></pre>
  
  <p>I suspect that some definition is missing but I do not know what as the <code>#pragma comment(lib, "d2d1")</code> was already added to the <code>pch.h</code>.</p>
  
  <p>I'm running Windows 10 Technical Preview build 9860 and VS Express 2013 update 3 on a virtual machine - VM-Ware.</p>
  
  <p>This is a sample project using effects and direct 2d: <a href="https://code.msdn.microsoft.com/windowsapps/Direct2D-Image-Effects-4819dc5b" rel="nofollow">Direct2D-Image-Effects</a></p>