Caliburn Micro Screen Activated Events

Question

I'm using Caliburn Micro and AvalonDock in my project. I try to handle events when screen was activated. My main view model is a 'Conductor.Collection.OneActive' and each tab "document" is a 'Screen'. I have a function in my main view model like this:

public void CheckAndRegisterDocument(DocumentViewModel document)
    {
        DocumentViewModel exists = _documents.FirstOrDefault((d) => { return d.Equals(document); });
        // if not exists - add it 
        if(exists == null) {
            document.Activated += Document_Activated;
            _documents.Add(document);
            Items.Add(document);
        }
        // activate and set property object
        ActivateItem(document);

        Properties.PropertiesObject = document.Properties;
    }

    // document activated event handler
    private void Document_Activated(object sender, ActivationEventArgs e) {
        ActiveDocument = sender as DocumentViewModel;
    }

But the function "Document_Activated" is not invoked. what am I doing wrong?

Are you sure that you are not trying to activate the same Screen second time in a row? — Anton Kedrov
And just note. There is no need to add document into Items collection manually, it will be added when you call ActivateItem(document). And it seems like _documents and ActiveDocument are just duplicating built-in conductor properties: Items and ActiveItem. — Anton Kedrov
Thanks for your reply. Yes, _documents and Items looks the same and they are )... it's a result of any my experiments. I was looking for decision. I don't understand why it not working. When the Activated event should invoke?... And, yes, I'm not trying to activate the same Screen second time. — R. Bolshakov
I wasn't able to reproduce this issue with Caliburn.Micro 3.0.1.0. I have made simple 'DocumentViewModel' class, which is derived from the 'Screen' class and as soon as I call ActivateItem(document), in the class derived from Conductor<Screen>.Collection.OneActive, Activated event fires without any trouble. You might try to enable logging and see what CM does when you try to activate your VM: buksbaum.us/2010/08/08/how-to-do-logging-with-caliburn-micro — Anton Kedrov
Hi. This is very usefull link for me, thanks. I'll try neccesarily. I think my trouble in some aspect of AvalonDock using... something I'm doing wrong — R. Bolshakov

DarinH DarinH · Accepted Answer · 2016-09-19T22:51:16

Instead of adding your document objects into a documents collection, add them to the already existing this.Items collection.

Also, each document object will need to inherit from Screen for it to participate.

That +should+ be enough to do the trick, but sometimes it can be necessary to tell Caliburn to "conduct" your viewmodels via ConductWith...

document.ConductWith(this)

there this is the current conductor viewmodel.

Caliburn Micro Screen Activated Events

1 Answers