title: DataGrid not triggering collection setter when a new item is added
body: <p>I have a data grid with two text columns and one checkbox column. Whenever a user manually enters values and tabs out to enter a new row, <code>ItemsSource</code> doesn't get updated (setter of the collection does not fire)</p>
  
  <pre><code>  &lt;DataGrid HeadersVisibility="Column" RowHeaderWidth="0" Grid.Row="2" Grid.ColumnSpan="2" ItemsSource="{Binding Parameters}" 
                                        CanUserAddRows="True" AutoGenerateColumns="False" CanUserDeleteRows="True" MinHeight="140" Style="{StaticResource ParametersDataGridStyle}"
                                        IsSynchronizedWithCurrentItem="True"&gt;
    &lt;DataGrid.Columns&gt;
     &lt;DataGridTextColumn Header="Key" Binding="{Binding Key}" Width="*"/&gt;
     &lt;DataGridTextColumn Header="Value" Binding="{Binding Value}" Width="*"/&gt;
     &lt;DataGridCheckBoxColumn Header="Post parameter" Binding="{Binding IsPostParameter}" Width="Auto" /&gt;
     &lt;/DataGrid.Columns&gt;
      &lt;/DataGrid&gt;
  </code></pre>
  
  <p>What to do to make this in sync with the property? Should I implement <code>INotifyCollectionChanged</code> ? Should I do it in a separate collection class like in this example:</p>
  
  <p><a href="http://www.c-sharpcorner.com/UploadFile/yougerthen/C-Sharp-and-xaml-within-a-silverlight-2-context-inotifycollectionchanged-implementation-part-v/" rel="nofollow">http://www.c-sharpcorner.com/UploadFile/yougerthen/C-Sharp-and-xaml-within-a-silverlight-2-context-inotifycollectionchanged-implementation-part-v/</a></p>