title: Remove a Canvas Child by tag
body: <p>I have an ellipse (prew) that I want to delete from canvas (canvas1) by tag ("p").
  I tried this, but it doesn't work:</p>
  
  <pre><code>var child = (from c in canvas1.Children
               where "p".Equals(c.Tag)
               select c).First();
  canvas1.Children.Remove(child);
  </code></pre>
  
  <p>It gave me this error:</p>
  
  <blockquote>
    <p>"Could not find an implementation of the query pattern for source type
    'System.Windows.Controls.UIElementCollection'.  'Where' not found. 
    Consider explicitly specifying the type of the range variable 'c'."</p>
  </blockquote>
  
  <p>How can I remove a <code>canvas</code> child by tag?</p>