title: OpenXML WordProcessingDocument to base64
body: <p>I have created a word document based on a template.</p>
  
  <p>Now I would like to get a base64 string of this new word document.</p>
  
  <p>I found some things about getting a memorystream and then translate it into base64 but I don't really understand how it works.</p>
  
  <p>Any idea to transform this <code>WordprocessingDocument doc</code> in <code>base64</code> ?</p>
  
  <p>Thanks</p>