I have a combo box in which I set up an ItemTemplate that looks something like this:

<ComboBox.ItemTemplate>
  <DataTemplate>
    <StackPanel Orientation="Horizontal">
      <TextBlock Text="{Binding Piece.NoPiece}" Width="50" />
      <TextBlock Text="{Binding Piece.Description}" Width="170" />
      <TextBlock Text="{Binding Piece.Categorie.NomCategorie}" />
    </StackPanel>
  </DataTemplate>
</ComboBox.ItemTemplate>

As you can see, I got three columns that let the user see different piece of information. However, I would like the selected item in the combo to display only the second column. In other word, is there a way to have an ItemTemplate that displays items in a different manner when you scroll down versus when it's closed and you only see the selection?