title: Databinding 2 WPF ComboBoxes to 1 source without being "linked"
body: <p>I have a master-detail scenario where I have 1 ComboBox listing companies from an ObjectDataSourceProvider.  Under that I have 2 ComboBoxes binding to the Contacts property from the current Company object.  I need to be able to select a different contact in each ComboBox; however, as soon as I change selection in one list the other list updates to the same contact.</p>
  
  <p>I have tried different settings (OneWay vs. TwoWay) but so far nothing seems to work.  Here is an excerpt of my XAML.</p>
  
  <pre><code>&lt;Page.Resources&gt;
      &lt;!-- This is a custom class inheriting from ObjectDataProvider --&gt;
      &lt;wg:CustomersDataProvider x:Key="CompanyDataList" /&gt;
  &lt;/Page.Resources&gt;
  
  &lt;Grid&gt;
      &lt;!--- other layout XAML removed --&gt;
      &lt;ComboBox x:Name="Customer" Width="150"
                ItemsSource="{Binding Source={StaticResource CompanyDataList},Path=Companies,Mode=OneWay}"
                DisplayMemberPath="Name"
                SelectedValuePath="Id"
                IsSynchronizedWithCurrentItem="True"
                SelectedValue="{Binding Path=Id, Mode=OneWay}" 
                VerticalAlignment="Bottom" /&gt;
  
      &lt;ComboBox x:Name="PrimaryContact" Width="150"
                DataContext="{Binding ElementName=Customer,Path=Items,Mode=OneWay}"
                ItemsSource="{Binding Path=Contacts,Mode=OneWay}"
                DisplayMemberPath="FullName"
                SelectedValuePath="Id"
                IsSynchronizedWithCurrentItem="True"
                SelectedValue="{Binding Path=Id,Mode=OneWay}" /&gt;
  
      &lt;ComboBox x:Name="AdminContact" Width="150"
                DataContext="{Binding ElementName=OwnerCustomer,Path=Items,Mode=OneWay}"
                ItemsSource="{Binding Path=Contacts,Mode=OneWay}"
                DisplayMemberPath="FullName"
                SelectedValuePath="Id"
                IsSynchronizedWithCurrentItem="True"
                SelectedValue="{Binding Path=Id,Mode=OneWay}" /&gt;
  
      &lt;!--- other layout XAML removed --&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p>I thought that creating a CollectionViewSource would be the way to go, but I have not been able to make that work.  Is there a simple way to do this so the PrimaryContact and AdminContact aren't linked?</p>