We had the same problem, here is a workaround:
create a global ResourceDictionary with an associated CodeBehind file
http://stackoverflow.com/questions/92100/is-it-possible-to-set-code-behind-a-resource-dictionary-in-wpf-for-event-handli
////////////////////////////////// XAML ////////////////////////////////////////////////////////
<!-- Template for a multiline ColumnHeader -->
<DataTemplate x:Key="columnManagerContentTemplate">
<TextBlock Text="{Binding}"
TextWrapping="WrapWithOverflow"
HorizontalAlignment="Stretch"
VerticalAlignment="Center" />
</DataTemplate>
<!-- Implicit style for a ColumnManagerCell -->
<Style TargetType="{x:Type xcdg:ColumnManagerCell}">
<EventSetter Event="Loaded" Handler="ColumnManagerCell_Loaded"/>
</Style>
////////////////////////////////// CodeBehind ////////////////////////////////////////////////////////
private void ColumnManagerCell_Loaded(object sender, RoutedEventArgs e)
{
ColumnManagerCell columnManagerCell = sender as ColumnManagerCell;
if (columnManagerCell != null)
{
if (columnManagerCell.ContentTemplate == null)
{
columnManagerCell.ContentTemplate = this["columnManagerContentTemplate"] as DataTemplate;
}
}
}