gistfile1.cs

public override void ViewWillAppear (bool animated)
{
    base.ViewWillAppear (animated);
    
    BeginInvokeOnMainThread (delegate () {
        this.Root = CreateRoot ();
    });
}

RootElement CreateRoot ()
{
    this.Root = new RootElement ("Root") {
        CreateSection_Items ()
    }
}

Section CreateSection_Items ()
{
    // Set up the section
    var itemsSection = new Section (string.Format ("Items ({0})", iSession.Unique.Materials.Count)); // iSession.Unique is a Singleton
    
    // Add the elements to the section
    itemsSection.AddAll (CreateElements_Items ());
    
    return itemsSection;
}

List <Element> CreateElements_Items ()
{
    var itemElements = new List<Element> ();

    foreach (var material in iSession.Unique.Materials) {
        itemElements.Add (new Element (material.Description));
    }

    return itemElements;
}