title: Filter Linq EXCEPT on properties
body: <p>This may seem silly, but all the examples I've found for using <code>Except</code> in linq use two lists or arrays of only strings or integers and filters them based on the matches, for example:</p>
  
  <pre><code>var excludes = users.Except(matches);
  </code></pre>
  
  <p>I want to use exclude to keep my code short and simple, but can't seem to find out how to do the following:</p>
  
  <pre><code>class AppMeta
  {
      public int Id { get; set; }
  }
  
  var excludedAppIds = new List&lt;int&gt; {2, 3, 5, 6};
  var unfilteredApps = new List&lt;AppMeta&gt;
                           {
                             new AppMeta {Id = 1},
                             new AppMeta {Id = 2},
                             new AppMeta {Id = 3},
                             new AppMeta {Id = 4},
                             new AppMeta {Id = 5}
                           }
  </code></pre>
  
  <p>How do I get a list of <code>AppMeta</code> back that filters on <code>excludedAppIds</code>?</p>