WPF nested objects databinding - wpf

Question

Hi I am having issues with understanding WPF databinding with nested objects.
I have a workgroup class containing a List of User_activation objects called ListMembers and I would like to display its properties. How do I access its nested properties? This class contains another object called User that has its username and ultimately I would like to display the username in the combobox instead of WPF_test.User_activation.
Below is the XAML code and corresponding layout:
<ListView x:Name="ListViewWorkgroups" VerticalAlignment="Top" Height="Auto" Width="Auto" ItemsSource="{Binding listWorkgroups}">
<ListView.View>
<GridView>
<GridViewColumn Width="auto" Header="Workgroup" DisplayMemberBinding="{Binding Name}"></GridViewColumn>
<GridViewColumn Width="auto" Header="Skills">
<GridViewColumn.CellTemplate>
<DataTemplate>
<ComboBox IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding ListSkills}" ></ComboBox>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
<GridViewColumn Width="auto" Header="Members">
<GridViewColumn.CellTemplate>
<DataTemplate >
<ComboBox IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding ListMembers}" ></ComboBox>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>
Layout: http://i50.tinypic.com/ydy5h.png
Thank you!

Answer 1

You need to set the ItemTemplate for the ComboBox
<ComboBox IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding ListMembers}" >
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding User.Username}"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
As an alternative, if you don't need anything complex you can bind the DisplayMemberPath
<ComboBox IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding ListMembers}" DisplayMemberPath="{Binding User.Username}"/>
You use the "." to access properties like you would in normal c# code

Answer 2

This is just a follow-up to the previous answer. I just discovered that in Bindings, you may use a leading period in a filesystem fashion:
<ComboBox ItemsSource="{Binding .ListMembers}">
<DataTemplate>
<TextBlock Text="{Binding .User.Username}"/>
</DataTemplate>
That syntax adds nothing semantically, but in some cases makes the statement more readable (and XAML can certaintly use that!)
Here's a better example:
<ComboBox ItemsSource="{Binding Caliber}" DisplayMemberPath=".Thickness" />
where Thickness is a property of Caliber.