ComboBox ItemsSource binding within a DataTemplate

Question

I'm trying to bind a combobox to a list of items (ObservableCollection) on my viewmodel. If I use something like this on my view:

<ComboBox ItemsSource="{Binding Path=Teams}" DisplayMemberPath="TeamName" />

everything is OK. But if I take that same combobox and use it as part of a datatemplate on another template used as the items template for a listbox, nothing shows up in the list. Pseudocode example:

<DataTemplate x:Key="test">
  <TextBlock Text="Team:" />
  <ComboBox ItemsSource="{Binding Path=Teams}" DisplayMemberPath="TeamName" />
</DataTemplate>

<ListBox ItemsSource="GamesCV" ItemTemplate="{StaticResource test}" />

I thought maybe I needed to add a relative source so I tried that, but no luck. I also tried giving my UserControl a name and using that as the ElementName on my combobox binding. I can't imagine this is as hard as I'm making it. I'm probably missing something obvious. Can anyone help? I can give more specifics if necessary, I'm just pressed for time right now.

Thanks, Dennis

Are there any binding errors in the Output Window in VS during runtime? Do the items in the GamesCV collection have a property named Teams? — nemesv
Is your DataContext ok ? Your GamesCV is a (observable) Collection, and one of the item of that collection (a GameCV) has a 'Teams' pblic property which is a (observable)Collection of items having a public property TeamName ? try checking this first. You might first add another property of a GameCV to check your test DataTemplate's DataContext (?GameName?). — GameAlchemist

H.B. H.B. · Accepted Answer · 2012-01-29T18:13:12

Maybe you forgot the DataContext in the path? If you use RelativeSource you target a framework element and no longer the DataContext, so this should do it:

{Binding DataContext.Teams, RelativeSource={RelativeSource AncestorType=ListBox}}

Also if you have trouble with bindings check for errors, they will tell you all you need to know.

ComboBox ItemsSource binding within a DataTemplate

2 Answers