VirtualQueryableCollectionView CurrentItem not loaded

[jura]

While using RadGridView with VirtualQueryableCollectionView and moving CurrentPosition with any of MoveCurrent* methods, I have found, that CurrentItem is not loaded when CurrentPosition changes to an index of not yet loaded item (in my case LoadSize is 50 and items are loaded from our WCF service) and thus CurrentItem is null.
The problem is in QueryableCollectionView.InternalGetItemAt where

return this.InternalList[index];

ignores items loading.

 

My fix for now is:

public class VirtualQueryableCollectionView<T> :
        Telerik.Windows.Data.VirtualQueryableCollectionView<T>
    {
        protected override void OnCurrentChanged(EventArgs args)
        {
            // fix not loaded CurrentItem is not loaded when CurrentPosition changes
            if (
                !IsCurrentBeforeFirst &&
                !IsCurrentAfterLast &&
                CurrentItem == null
                )
            {
                SetCurrent(GetItemAt(CurrentPosition), CurrentPosition);
            }
            base.OnCurrentChanged(args);
        }
    }

It has a drawback that OnCurrentChanged is called twice when this fix is effective.

[jura]

I forgot to mention that I am Marek Ištvánek using Jura`s account ;-)

[Dimitrina]

Hi,

You are indeed right. The MoveCurrent methods are not respected by VirtualQueryableCollectionView.

In order to get better overview on what the progress of this issue is, I would suggest you to submit it on the Feedback Portal. You can also refer to the details posted at the end of this reply. That way you may follow the item and get notified when there is a change in the status of the report. 

Thank you for sharing the workaround you came up with the community.

Regards,
Dimitrina
Telerik

[jura]

Reported here:
http://feedback.telerik.com/Project/143/Feedback/Details/167237-virtualqueryablecollectionview-currentitem-not-loaded

Marek