Thx Andrew.

When I bind the ItemsSource property of the TabGroupPane to the LoadedPlugins property in the ViewModel from the previously mentioned MSDN article I get the following error:

Error loading plugin. InvalidOperationException: A TabGroupPane can only contain 'ContentPane' and 'ContentPanePlaceholder' instances. etc etc.

Any ideas how to get a round this? The LoadedPlugins property is returning a Collection of Plugin objects which kinda hints at Tacho's response that it is not supported.

That is correct. You cannot use the ItemsSource because the ItemsSource of an ItemsControl will automatically create an element for each data item and add it to the associated ItemsPanel. The xamDockManager needs to be able to remove a pane from the current location in order to allow moving it elsewhere, unpinning it, etc. You would need to either create the ContentPanes in xaml, create them programmatically or use a behavior like the article that I mentioned in my previous reply.

Boy sorry for being so dense but can you show me how you can bind a contentpane to the "SelectedPlugin" property in the ViewModel in the MSDN article.

SelectedPlugIn is returning a Plugin Object which you say (above in this thread) is a HwndHost.

I don't know that I can redistribute that article's source so I won't repost a modified version of that sample but the steps would be:

• Add a reference to System.Windows.Interactivity (since Brian's post uses Behavior<T> from that)
• Add TabGroupPaneItemsSourceBehavior.cs from Brian's sample to the project
• Comment out the TabControl in the MainWindow.xaml
• Comment out the code in the Window_Loaded (since that is specific to their being a TabControl present)
• That article uses a command to remove the plugin even though the PlugIns collection is a modifiable ObservableCollection<T> so you either modify that article's sample to perform the Dispose when the RemoveItem is invoked (or if you can assume that Clear won't be used then via the CollectionChanged event) -or- you have to modify Brian's TabGroupPaneItemsSourceBehavior such that it can invoke a command when the pane is closed. I'll go with the latter for simplicity since the sample has a command defined. So for that you would define a property on that class (likely of type ICommand) and then execute it from within the Container_Closed event handler.

e.g. Define the property

<code>

public static readonly DependencyProperty ClosedCommandProperty =
  DependencyProperty.Register("ClosedCommand",
  typeof(System.Windows.Input.ICommand),
  typeof(TabGroupPaneItemsSourceBehavior));

public System.Windows.Input.ICommand ClosedCommand
{
  get { return (System.Windows.Input.ICommand)GetValue(ClosedCommandProperty); }
  set { SetValue(ClosedCommandProperty, value); }
}

</code>

And modify add the part to use it.

e.g.

<code>

private void Container_Closed(object sender, PaneClosedEventArgs e)
{
  ContentPane contentPane = sender as ContentPane;
  if (contentPane != null)
  {
    contentPane.Closed -= Container_Closed; //no memory leaks

    var item = contentPane.DataContext;

    if (ItemsSource != null && ItemsSource.Contains(item))
      ItemsSource.Remove(item);

    RemoveBindings(contentPane);

    if (null != this.ClosedCommand)
      this.ClosedCommand.Execute(item);
  }
}

</code>

I've attached a modified version of Brian's file which has these two changes.

Then you just add something like the following in place of the TabControl in the MainWindow.xaml:

<code>

<igWpf:XamDockManager
  x:Name="dockManager"
  xmlns:igWpf="http://schemas.infragistics.com/xaml/wpf"
  xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
  xmlns:dockMvvm="clr-namespace:XamDockManager_MVVM">
  <igWpf:XamDockManager.Panes>
    <igWpf:SplitPane>
      <igWpf:TabGroupPane x:Name="plugins">
        <i:Interaction.Behaviors>
          <dockMvvm:TabGroupPaneItemsSourceBehavior
            ClosedCommand="{Binding DataContext.CloseTabCommand, ElementName=dockManager}"
            HeaderMemberPath="Title"
            ItemsSource="{Binding LoadedPlugins}">
            <dockMvvm:TabGroupPaneItemsSourceBehavior.ItemTemplate>
              <DataTemplate >
                <ContentPresenter Content="{Binding View}" />
              </DataTemplate>
            </dockMvvm:TabGroupPaneItemsSourceBehavior.ItemTemplate>
          </dockMvvm:TabGroupPaneItemsSourceBehavior>
        </i:Interaction.Behaviors>
      </igWpf:TabGroupPane>
    </igWpf:SplitPane>
  </igWpf:XamDockManager.Panes>
</igWpf:XamDockManager>

</code>

This works great. Thanks

Just one more question...

With the TabGroup is there a method/property to have the tabs tile. I know you can do this my manually dragging the tabs but it would be nice if there was some way for, say 4 tabs, to tile automatically.

I don't know what you mean by making tabs tile. If you mean having it create multiple ContentPanes within a SplitPane in which case those are not tabs and no, Brian's behavior wouldn't do that. You would need to write your own custom attached behavior. You could try commenting on his blog post - maybe he has something like that already but I doubt it given that the post is about his "TabGroupPaneItemsSourceBehavior".