title: Read BuiltInDocumentProperties/CustomDocumentProperties alway null with Word 2010?
body: <p>I want to read out the BuiltInDocumentProperties/CustomDocumentProperties of an Word document. The following Source always return null :-(</p>
  
  <pre><code>using Microsoft.Office.Core;
  using Word = Microsoft.Office.Interop.Word;
  .....
      private void toolStripMenuItemTmp_Click(object sender, EventArgs e)
      {
          Word.Application word = new Word.Application();
          Word.Document document = word.Documents.Open(@"C:\Users\fillibuster\Desktop\docproperty.docx");
          DocumentProperties properties = (DocumentProperties)document.CustomDocumentProperties;
          if (properties != null)
          {
              foreach (Microsoft.Office.Core.DocumentProperty item in properties)
              {
                  MessageBox.Show(item.Name.ToString() + item.Value.ToString());
              }
          }
          else
          {
              MessageBox.Show("null");
          }
  
      }
  </code></pre>
  
  <p>What's wrong with the source? CustomDocumentProperties and BuiltInDocumentProperties are available and filled in the document!</p>