Populate ComboBox in GridView header with column data - wpf

Question

I want to have a ComboBox in the header cells of my GridView (currently inside of a ListView) populated with the data from that column. To be used a bit like the 'auto filter' feature in Excel.
The problem I have is I can't get to the data for the column from inside the header cell. At the moment, I have something like this:
<Grid>
<Grid.Resources>
<DataTemplate x:Key="headerTemplate">
<StackPanel>
<ComboBox></ComboBox>
<TextBlock FontSize="16" Text="{Binding}" Grid.Row="1" HorizontalAlignment="Center"/>
</StackPanel>
</DataTemplate>
</Grid.Resources>
<ListView Width="400" Height="200">
<ListView.View>
<GridView ColumnHeaderTemplate="{StaticResource headerTemplate}">
<GridViewColumn Header="Name" DisplayMemberBinding="{Binding Name}"/>
<GridViewColumn Header="Namespace" DisplayMemberBinding="{Binding Namespace}"/>
</GridView>
</ListView.View>
<x:Type TypeName="Visual"/>
<x:Type TypeName="UIElement"/>
<x:Type TypeName="FrameworkElement"/>
</ListView>
</Grid>
But I'm not sure how to get the data to populate the combo boxes in the header. What's the best way of doing this?

Answer 1

A quick and dirty way would be something like this:
<Grid.Resources>
<DataTemplate x:Key="headerTemplate">
<StackPanel>
<ComboBox ItemsSource="{Binding Path=Items, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ListView}}}" DisplayMemberPath="{Binding}"/>
<TextBlock FontSize="16" Text="{Binding}" Grid.Row="1" HorizontalAlignment="Center"/>
</StackPanel>
</DataTemplate>
</Grid.Resources>
If you really need a filter-like list, you'll have to figure out how to get distinct values only.