New Post: What's the best prism region to hold MDI windows?

Hi All,

Currently I am using Prism 4.1 as my component application development platform. I am using WPFMDI(http://wpfmdi.codeplex.com/) so that i can hold each view of module as a child of MdiContainer, in order to make this, i wrote below custom region adaptor:

protected override void Adapt(IRegion region, MdiContainer regionTarget)

    {
        region.Views.CollectionChanged += (sender, e) =>
        {
            switch (e.Action)
            {
                case NotifyCollectionChangedAction.Add:
                    foreach (FrameworkElement element in e.NewItems)
                    {
                        IView view = element as IView;
                        if (null != view)
                        {
                            BaseViewModel viewModel = view.GetViewModel();
                            if (null != viewModel)
                            {
                                MdiChild mdiChild = new MdiChild();
                                if (null != viewModel.ViewObject)
                                {
                                    mdiChild.Title = viewModel.ViewObject.Title;
                                    mdiChild.Height = viewModel.ViewObject.Height;
                                    mdiChild.Width = viewModel.ViewObject.Width;
                                }
                                mdiChild.Content = element;
                                regionTarget.Children.Add(mdiChild);
                                IRegionManagerService regionManagerService = ServiceLocator.Current.GetInstance<IRegionManagerService>();
                                regionManagerService.AddView(viewModel.ViewObject);
                            }
                        }
                    }
                    break;

                case NotifyCollectionChangedAction.Remove:
                    foreach (UIElement elementLoopVariable in e.OldItems)
                    {
                        var element = elementLoopVariable;

                        //if (regionTarget.Items.Contains(element))
                        //{
                        //    regionTarget.Items.Remove(element);
                        //}
                    }
                    break;
            }
        };
    }

However, I need to implement below features:

when a view is requested via RequestNavigate, if it's not opened yet(I check this via Uri with query parameter), the view is shown as a child of mdicontaner.
if it's opened already, I need to activate it as a child of mdicontaner.

Could anyone give me some idea which region i should use, i am currently using MdiContainer as prism container, but i don't think it's good, there should be some better solution...