title: The member is not recognized or is not accessible
body: <p>In my WPF I have</p>
  
  <pre><code>public class AttachedColumnBehavior
  {        
  
  
      public static readonly DependencyProperty MappedValuesProperty =
              DependencyProperty.RegisterAttached("MappedValues",
              typeof(MappedValueCollection),
              typeof(AttachedColumnBehavior),
              new UIPropertyMetadata(null, OnMappedValuesPropertyChanged));
  
  }
  
     public static MappedValueCollection GetMappedValues(DependencyObject dataGrid)
      {
          return (MappedValueCollection)dataGrid.GetValue(MappedValuesProperty);
      }
  
      public static void SetMappedValues(DependencyObject dataGrid, MappedValueCollection value)
      {
          dataGrid.SetValue(MappedValuesProperty, value);
      }
  </code></pre>
  
  <p>and in my Xaml I have </p>
  
  <pre><code>&lt;DataGrid ItemsSource="{Binding MyCollectoin}" x:Name="myGrid" 
  
                    loc:AttachedColumnBehavior.MappedValues="{Binding MyCollectionValues}"                      
                    AutoGenerateColumns="False"&gt;
              &lt;DataGrid.Columns&gt;
  </code></pre>
  
  <p>But I am getting <code>The Member MappedValues is not recognized or is not acessible</code> error.</p>