title: Ignore a property in the DataSource to check HasChanges
body: <p>I got a problem with one of my class.</p>
  
  <p>In Silverlight, I got a dataGrid, fill with my class Objects.</p>
  
  <p>I add it a checkBox column binding into a property ÌsSelect` in my class.</p>
  
  <p>I use it to check if the object is select or not.</p>
  
  <p>The thing is, when I checked, Unchecked into the columns, it see a change in my Object, because the value of IsSelect has been changed.</p>
  
  <p>Can I add, in my class, a metadata, or something else to tell my dataSource : 'Ignore this column to check if there is changes'?</p>
  
  <p>I can use <code>[Key()]</code> to know the primary key, but is there something like  <code>[Ignore()]</code>?</p>
  
  <p>I found something as NotMapped, but it tells me I am missing an assembly while I got </p>
  
  <pre><code>System.ComponentModel.DataAnnotations
  </code></pre>
  
  <p>It seems, NotMapped exist only in 4.5, so is there something I can use instead?</p>
  
  <p>Thank you.</p>