Prism 4 Splash Screen with MEF bootstrapper

Question

I have a prism 4 application using an MEF bootstrapper. I have implemented a splash screen from the bootstrapper and want to provide the user with module info (as they are loaded) while the module manager is loading the app/modules.

I think I need to subscribe to the LoadModuleCompleted event in the module manager. I cannot do this because when I resolve the module manager with the container in the MEF bootstrapper the PRISM framework calls OnImportsSatisfied which loads all the modules. (This is too late since I want to listen for this).

How can I display a splash window with a progress bar displaying module info/progress?

Many thanks!

You can check out this project. It uses a Unity bootstrapper, but you may find it useful. — Adi Lester

Scott Wegner Scott Wegner · Accepted Answer · 2012-08-25T00:27:29

If you control the composed parts that are imported into your project, you can implement IPartImportsSatisfiedNotification on each and have them report their own progress to some imported progress monitor class:

public interface IProgressMonitor
{
    void ReportComposed(Type type);
}

[Export(typeof(IProgressMonitor))]
public class ProgressMonitor : IProgressMonitor
{
    public ProgressMonitor()
    {
        var loadHeuristic = this.GetPreviousLoadProgress();
        if (loadHeuristic == null)
        {
            // Never been loaded before, so it's unclear how long it will take
            // Set indeterminate progress bar.
        }
        else
        {
            // Use previous load times to estimate progress.
            _loadHeuristic = loadHeuristic;
            _progress = 0;
        }
    }

    public void ReportComposed(Type type)
    {
        if (_loadHeuristic != null)
        {
            this.IncrementProgress();
        }
    }
}

[Export]
public class FooExport : IPartImportsSatisfiedNotification
{
    [Import]
    internal IProgressMonitor ProgressMonitor { get; set; }

    public void OnImportsSatisfied()
    {
        this.ProgressMonitor.ReportComposed(typeof(FooExport));
    }
}

Prism 4 Splash Screen with MEF bootstrapper

1 Answers