WPF Toolkit Combobox DisplayMemberPath not working - wpf

Question

I am using the very handy WPF Toolkit Xaml to have a nice GUI. I am having issues however with the combobox items. I have successfully bound to the combobox control, but the items in the dropdown show the bound object, not the displaymember. Funny enough, when I select an item, the correct displaymember is shown in the textbox.
Any help would be appreciated!
Mark.
My XAML to display the combobox:
<ComboBox Name="uxFeatureGroup" Margin="17,16,0,0" Height="23"
HorizontalAlignment="Left"
VerticalAlignment="Top" Width="162"
DisplayMemberPath="FeatureGroupName"></ComboBox>
and the XAML in the WPF Template:
<Style TargetType="{x:Type ComboBox}">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
<Setter Property="VerticalContentAlignment" Value="Center" />
<Setter Property="FontFamily" Value="Trebuchet MS" />
<Setter Property="FontSize" Value="12" />
<Setter Property="Padding" Value="6,2,25,2" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ComboBox}">
<ControlTemplate.Resources>
<Storyboard x:Key="FocusedOn">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="FocusVisualElement" Storyboard.TargetProperty="(UIElement.Opacity)">
<SplineDoubleKeyFrame KeyTime="00:00:00.1000000" Value="1" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
<Storyboard x:Key="FocusedOff">
<DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="FocusVisualElement" Storyboard.TargetProperty="(UIElement.Opacity)">
<SplineDoubleKeyFrame KeyTime="00:00:00.3000000" Value="0" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</ControlTemplate.Resources>
<Grid>
<ToggleButton Grid.Column="2" Template="{DynamicResource ComboBoxToggleButton}" x:Name="ToggleButton" Focusable="false" IsChecked="{Binding Path=IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" ClickMode="Press" />
<ContentPresenter HorizontalAlignment="Left" Margin="3,3,23,3" x:Name="ContentSite" VerticalAlignment="Center" Content="{TemplateBinding ComboBox.SelectionBoxItem}" ContentTemplate="{TemplateBinding ComboBox.SelectionBoxItemTemplate}" ContentStringFormat="{TemplateBinding ComboBox.SelectionBoxItemStringFormat}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" IsHitTestVisible="False" />
<TextBox Visibility="Hidden" Template="{DynamicResource ComboBoxTextBox}" HorizontalAlignment="Left" Margin="3,3,23,3" x:Name="PART_EditableTextBox" Style="{x:Null}" VerticalAlignment="Center" Focusable="True" Background="Transparent" IsReadOnly="{TemplateBinding IsReadOnly}" />
<Rectangle x:Name="DisabledVisualElement" Fill="{DynamicResource DisabledBackgroundBrush}" Stroke="{DynamicResource DisabledBorderBrush}" RadiusX="0" RadiusY="0" IsHitTestVisible="false" Opacity="0" />
<Rectangle x:Name="FocusVisualElement" Margin="-1" Stroke="{DynamicResource FocusBrush}" StrokeThickness="1" IsHitTestVisible="false" Opacity="0" />
<Popup IsOpen="{TemplateBinding IsDropDownOpen}" Placement="Bottom" x:Name="Popup" Focusable="False" AllowsTransparency="True" PopupAnimation="Slide" Margin="0,1,0,0">
<Grid MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{TemplateBinding ActualWidth}" x:Name="DropDown" SnapsToDevicePixels="True">
<Border x:Name="DropDownBorder" Margin="0,-1,0,0" BorderBrush="{DynamicResource ControlBorderBrush}" BorderThickness="1" CornerRadius="0,0,3,3" Background="{DynamicResource ControlBackgroundBrush}">
<ScrollViewer Margin="4,6,4,6" SnapsToDevicePixels="True" HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto" CanContentScroll="True">
<StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Contained" />
</ScrollViewer>
</Border>
</Grid>
</Popup>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsFocused" Value="True">
<Trigger.ExitActions>
<BeginStoryboard Storyboard="{StaticResource FocusedOff}" x:Name="FocusedOff_BeginStoryboard" />
</Trigger.ExitActions>
<Trigger.EnterActions>
<BeginStoryboard Storyboard="{StaticResource FocusedOn}" />
</Trigger.EnterActions>
</Trigger>
<Trigger Property="HasItems" Value="false">
<Setter Property="MinHeight" Value="95" TargetName="DropDownBorder" />
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource DisabledForegroundBrush}" />
<Setter Property="Opacity" TargetName="DisabledVisualElement" Value="1" />
</Trigger>
<Trigger Property="IsGrouping" Value="true">
<Setter Property="ScrollViewer.CanContentScroll" Value="false" />
</Trigger>
<Trigger Property="AllowsTransparency" SourceName="Popup" Value="true">
<Setter Property="CornerRadius" Value="4" TargetName="DropDownBorder" />
<Setter Property="Margin" Value="0,2,0,0" TargetName="DropDownBorder" />
</Trigger>
<Trigger Property="IsEditable" Value="true">
<Setter Property="IsTabStop" Value="false" />
<Setter Property="Visibility" Value="Visible" TargetName="PART_EditableTextBox" />
<Setter Property="Visibility" Value="Hidden" TargetName="ContentSite" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

Answer 1

Try this.
In the ComboBoxItem template for the the theme you're using, remove the Content and ContentTemplate attributes from ContentPresneter Element.
So, instead of this:
<ContentPresenter x:Name="contentPresenter"
Content="{TemplateBinding Content}"
ContentTemplate="{TemplateBinding ContentTemplate}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
Margin="{TemplateBinding Padding}" />
use this:
<ContentPresenter x:Name="contentPresenter"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
Margin="{TemplateBinding Padding}" />