title: Binding-Source CancelEdit() doesn't work for saved objects in entity framework
body: <p>My app is C# winform.</p>
  
  <p>I saved my data in sql database with entity framework, but when I want to edit them the binding-source when user changes the data, but don't want to update the current object <code>CancelEdit()</code> doesn't work.</p>
  
  <p>My binding-source datasorce is a table of entity framework.</p>
  
  <p>My code when form loads:</p>
  
  <pre><code>myEntity contex = new myEntity();
  myBindingSource.DataSource = contex.myTable;
  </code></pre>
  
  <p>And code for cancel button:</p>
  
  <pre><code>myBindingSource.CancelEdit();
  </code></pre>