Caliburn Micro: How to bind ActivateItem to selectionEvents in Conductors

Question

As can be seen in the SimpleMDI Caliburn Micro project there are some conventions that bind the selectionEvent in tabControls to the ActivateItem in a Conductor. I can't really see any mention of what this event might be.

However when you have a control that doesn't fullfill these convention I'm lost on how to manage them myself.

I have a Telerik RadTreeView that I want to manage with a conductor to be able to load on demand the childs of nodes (via WCF call).

Here is where I am at:

<telerik:RadTreeView x:Name="Items"
                     cal:Message.Attach="[Event Selected] = [ActivateItem($dataContext)]"  />

Passing $dataContext is wrong because that way he passes the Conductor itself, $SelectedItem returns null.

So my rather simple question is threefold.

1) If RadTreeView is a Selecetor why doesn't the basic CM convention work with it,

2) What event should I use to call ActiveItem

3) What could I pass in.

I've actually changed how it's supposed to work. Yes I wanted to display hierarchical but it would all implement IActivate thing. Problems was connecting a event in the treeview with the activation logic of the conductor. I had no idea how to pass the selected items as a parameter. — Ingó Vals, Jul 09 '12 at 17:46

Derek Beattie · Accepted Answer · 2012-07-10T15:20:07.160

This might help understand the different approaches to doing treeviews and mvvm.

I was using the RadTreeView also and I ended up sending the events to the ViewModel that hosted the Items collection of TreeViewItemViewModel. When an action/event, for example, Edit, was sent to the MainViewModel, I had a method like:

 public void Edited(object sender, RadTreeViewItemEditedEventArgs e)
        {
            var treeViewItemViewModel = e.NewValue as IEditable;
            if (treeViewItemViewModel == null) return;

            treeViewItemViewModel.EndEdit();
        }

So this worked at any level in the tree and also worked for having different behaviors, checking to see if the interface for different things was implemented.

xaml for the RadTreeView

 <telerik:RadTreeView x:Name="MyTree"
                                     Grid.Row="1"
                                     Margin="0,20,0,0"
                                     VerticalAlignment="Stretch"
                                     FontSize="16"
                                     FontFamily="{StaticResource MainFontFamily}"
                                     ItemsSource="{Binding Children, Mode=TwoWay}"
                                     ItemTemplate="{StaticResource HierarchicalDataTemplate}"
                                     ItemEditTemplateSelector="{StaticResource ItemEditTemplateSelector}"
                                     ItemEditTemplate="{x:Null}"
                                     IsLoadOnDemandEnabled="True"
                                     IsEditable="True"
                                     IsDragDropEnabled="True"
                                     DropExpandDelay="00:00:01"
                                     telerik:TextSearch.TextPath="ItemId"
                                     PathSeparator="|"
                                     cal:Message.Attach="
                                    [Event LoadOnDemand] = [Action LoadOnDemand($eventArgs)];
                                    [Event PreviewDragStarted] = [Action PreviewDragStarted($source,$eventArgs)];
                                    [Event PreviewDragEnded] = [Action PreviewDragEnded($source,$eventArgs)];
                                    [Event DragEnded] = [Action DragEnded($source,$eventArgs)];
                                    [Event Edited] = [Action Edited($source,$eventArgs)];
                                    [Event EditCanceled] = [Action EditCanceled($source,$eventArgs)]"/>

Well Caliburn.Micro should help you avoid all mess like this. So you could just create a normal method and pass something as a parameter through. The parameter should be the item I just selected, but I was hoping I could say that in the cal:Message.Attach — Ingó Vals, Jul 10 '12 at 14:24
I am using Message.Attach. ` [Event Edited] = [Action Edited($source,$eventArgs)];` I edited to show the xaml for the TreeView. — Derek Beattie, Jul 10 '12 at 15:17
Let me know if you have any more questions, I can provide a better example. — Derek Beattie, Jul 10 '12 at 18:19

Caliburn Micro: How to bind ActivateItem to selectionEvents in Conductors

1 Answers1