VirtualQueryableCollectionView Refresh problem on Windows10

[DenisCL]

Hi,

We are using VQCV (Telerik 2016.2.503.40) to virtualize data to RadGridView from the server side to client, sometimes the grid doesn't refresh correctly the new added items (we had a workaround with an explicit call to the .Refresh() function in the end of the data loading routine), unfortunately this causes a freeze of the main Thread on Windows10.

This problem exists also in the telerik Demo panel (see the attached file).

01.Task.Factory.StartNew(() =>

02.{

03.    // Getting data from the server Side

04.    return result;

05. 

06.}).ContinueWith(finLazyLoading =>

07.{

08.   // DataVirtualisationRoutine...

09. 

10.    MyVQCV.VirtualItemCount = collection.ItemsCount;

11. 

12.    MyVQCV.Load(currentOffset, collection.Items);

13. 

14.    // If we call the refresh here it occurs the bug on Win10 (total freeze of the app).

15. 

16.}, TaskScheduler.FromCurrentSynchronizationContext()).ContinueWith(fixwin10 =>

17.{

18.    // This call causes an infinite loop... :(


19.

20.    MyVQCV.Refresh();

21. 

22.}, TaskScheduler.FromCurrentSynchronizationContext());

Can we have a fixe for this please or a working solution, we don't know how to do.

Thank you!

[Yoan]

Hello,

I will need additional time in order to further investigate this issue. I will let you know as soon as I have more information on the matter. Thank you in advance for your patience and understanding.

Regards,
Yoan
Telerik by Progress

[Yoan]

Hello,

Thank you for your patience.

I've tried to reproduce the problem on our Silverlight demos and it seems you are right - there are missing items in the control (a blank space). However, I was able to reproduce it not on GridView example but in the TreeView (Binding to Various Controls). Moreover, I can't reproduce it constantly in the demo. However, I don't believe that this is your problem since your application is hanging and the scenario is with the Refresh method of the VQCV after inserting an item. Please note that the VirtualQueryableCollectionView is designed for ReadOnly purposes and it is not recommended to be used in scenarios where an update is needed as stated in VQCV's help article. However, I will be glad to see if we can assist you in your scenario. It will be great if you can isolate the hanging problem in a sample project which can be debugged on our side. 

Regards,
Yoan
Telerik by Progress

[DenisCL]

Hello,
Your welcome.

Alright, you'll find the sample project

"https://mega.nz/#!gKBxyLwB!y5fe3UnM4gFxRJO5HTGP9yqmJBx6nyOJ5Tr1dlyeyHU"

(It will occurs when you scroll to the next page, then you will click on a column and then you will scroll again).
We hope to have a solution for this.
If you can fixe the white pages problem, it will be awesome, because this is a workaround of it (RadGridView send white page to the visual tree if the user scroll's fastly ^^)

Ragards

[Yoan]

Hi,

Thank you for the sample project. May I ask you to test it with our latest official version (2017.2.614) and let me know how it works at your side? I've tested it and everything works as expected.

I'm looking forward to hearing from you.

Regards,
Yoan
Progress Telerik

[DenisCL]

Hi,

Your welcome. it's done with Telerik 2017 UI for WPF R2 2017 and it works, everything is alright.

Thank you so much.

Regards,