ActivateItem not working in Caliburn.Micro

Question

I am using Caliburn Micro for MVVM. In my MainView (shell), I have two controls. One hosts a RibbonView and another ContentControl which loads contents depending on the RibbonView menu selection. Here is the MainView (shell)

MainView (shell)

<Window x:Class="HotelReservation.Main.Views.MainView">
    <DockPanel>

        <ContentControl x:Name="RibbonView" DockPanel.Dock="Top"/>

        <Grid DockPanel.Dock="Bottom" VerticalAlignment="Stretch" >
            <ContentControl x:Name="ActiveItem"/>
        </Grid>
    </DockPanel>
</Window>

RibbonView

<Ribbon Margin="0,-20,0,0">
    <RibbonTab Header="Room Band">
        <RibbonGroup>
            <RibbonButton Label="List" x:Name="RoomBandMain"
                             LargeImageSource="/HotelReservation.Global;component/Images/room-band-list-icon.png">
            </RibbonButton>
        </RibbonGroup>
    </RibbonTab>
</Ribbon>

RibbonViewModel

public class RibbonViewModel : Conductor<object> {

    public void RoomBandMain() { //Load in ActiveItem of MainView
        ActivateItem(container.GetExportedValue<RoomBandMainViewModel>());
    }
}

As can be seen, I am trying to load RoomBandMainViewModel in the <ContentControl x:Name="ActiveItem"/> The issue is that it is not loaded and I get a blank screen even though ActivateItem(container.GetExportedValue<RoomBandMainViewModel>()) code runs. I think that the <ContentControl x:Name="ActiveItem"/> exists not in RibbonView but its parent MainView , and hence the ActivateItem doesn't work.

How to resolve this issue.

Edit:

I had to set the DataContext of the <ContentControl x:Name="ActiveItem"/> to RibbonViewModel, so that ActiveItem is now property of RibbonViewModel and not MainViewModel. MainViewModel looks like below

So the MainView (shell) is now as follows

<Window x:Class="Conductor_Main.Views.MainView">

    <DockPanel>
        <ContentControl x:Name="RibbonView" DockPanel.Dock="Top"/>

        <Grid DockPanel.Dock="Bottom" VerticalAlignment="Stretch" Background="Green"  
               DataContext="{Binding RibbonView}">

            <ContentControl x:Name="ActiveItem" />
        </Grid>
    </DockPanel>
</Window>

Now the <ContentControl x:Name="ActiveItem" /> actually belongs to the RibbonViewModel.

Answer 1

What you have here is some kind of lifecycle of your windows. This has to be handled by the parent window of your ActiveItem .

The way to get this done the caliburn.micro way is to have a Conductor above the ActiveItem . In your case this is the MainWindow .

Your RibbonViewModel can be a Conductor, too. But only for it's own children. There can be more than one conductor.

From the caliburn documentation

Once you introduce the notion of a Screen Activation Lifecycle into your application, you need some way to enforce it. This is the role of the ScreenConductor. When you show a screen, the conductor makes sure it is properly activated.

Which is quite a direct way of saying: If you have activation / life cycle, then use a conductor.