Data virtualization using pages

[Beryl Wilson]

We have IEnumerable<Product> object whose count is 3000. It would take 800 milliseconds to loop through 30 objects. But would take around 1 minute to loop through 3000 objects. I created a RadDataPager and set the page size as 30 and the source to IEnumerable<Product> object whose count is 3000. Then I had set the ItemSource of the grid as PagedSource. I expect RadDataPager to loop through only 30 objects at any given point in time. But unfortunately it loops through entire 3000 objects and defeats the purpose of paging. Am I missing some thing.

Thanks in advance,
Beryl Wilson

[Beryl Wilson]

Need help!!! Please let me know if am not clear. I'm almost stuck here and in the process of finalizing a 3rd party grid control.

[Rossen Hristov]

Hi Beryl Wilson,

Can you please open a separate support ticket and send us the sample project. We will then examine it and see what is going on.

Thanks in advance. We are looking forward to hearing from you.

Best wishes,
Ross
the Telerik team

[Rossen Hristov]

Hi Beryl Wilson,

Actually, you do not need to send us a project.

The pager needs to know the total count of the items so it can calculate the number of pages. It takes the total count and divides it by the page size.

In case you want to achieve endless paging, i.e. where the total number of pages is not known, you will have to implement the IPagedCollectionView interface and return appropriate values. For example, for the ItemCount property you can return hard-coded 3000 if you are sure that they will be always 3000. By implementing the IPagedCollectionView you will ensure that the pager will communicate with your implementation.

A similar implementation an be seen in the online example called Endless Paging.

My blog post explains the basic stuff about paging.

Regards,
Ross
the Telerik team

[Beryl Wilson]

Thanks for your reply. I would try this way and would let you know about the same.