title: EWS - how do I find all incomplete tasks?
body: <p>I am using Exchange Web Services to try to get a list of all Outlook tasks which are not complete.</p>
  
  <p>I have an instance of ExchangeService, and attempt to find all incomplete tasks like this:</p>
  
  <pre><code>SearchFilter searchFilter = new SearchFilter.IsNotEqualTo(TaskSchema.Status, TaskStatus.NotStarted);
  FindItemsResults&lt;Item&gt; tasks = service.FindItems(WellKnownFolderName.Tasks, searchFilter, view);
  </code></pre>
  
  <p>However, on the last line, I get a "ServiceResponseException: The specified value is invalid for property." This seems weird to me because <a href="http://msdn.microsoft.com/en-us/library/microsoft.exchange.webservices.data.task.status%28v=exchg.80%29.aspx" rel="nofollow">the EWS documentation explicitly states</a> that the Task.Status is supposed to be one of the TaskStatus enumeration values. Creating a SearchFilter which compares against a string value does not cause an exception, but I haven't tried any of the other enumeration options to see whether they give the same behavior.</p>