Intercepting scroll thumb drag events

[scottw]

I am capturing scroll events (via gvLibrary.TableElement.VScrollBar.Scroll += this.gvLibrary_Scroll;) so that I can call a method on a lazy-loader class to update records in my buffer.  It's designed so that the 100,000+ records won't have to load all at once, but instead we load just a few pages of data at a time.  Each time the scroll is CLICKED, I am successfully able to trap the event and update my lazy-loaded queue.  However, if I drag the scroll bar, the event does not appear to fire.  Is there another event that I can use to handle when the scroll thumb is dragged?

Thank you,

VSmirk

[Richard Slade]

Hello,

As far as I'm aware there is no event for this. However, if you are wishing to emulate paging, then there is an article here that descibes emulating paging with LINQ and 1 million records.

Hope that helps
Richard

[Svett]

Hi VSmirk,

I am not able to reproduce the issue. The event is fired on my side. I would kindly ask you to open a new support ticket where you can send a sample project where your scenario is illustrates.

Kind regards,
Svett
the Telerik team

[Jeff]

Does anyone know if there's an updated URL for the link Richard posted?

[Stefan]

Hi,

The link you are looking for is here: http://blogs.telerik.com/winformsteam/posts/08-09-02/emulating-paging-with-radgridview-for-winforms-and-linq-with-1-million-records.aspx. However, this article is quote outdated. RadGridView now supports paging out of the box. More information about it is available in our documentation: http://www.telerik.com/help/winforms/gridview-paging-overview.html.

If you need to load great amounts of data, you can look at the following article: http://www.telerik.com/support/kb/winforms/gridview/details/high-performance-with-radgridview-and-virtual-mode-including-filtering-sorting-and-grouping.

I hope that you find this information useful.

Regards,
Stefan
Telerik

 

 

[Jeff]

Thank you, Stefan.  At first glance, those articles do look useful.  Regarding the OP's original question, it would sure be nice if the GridView, which "is-a" ScrollableControl, would honour the contract and emit Scroll events.  To load more data is not the only use of that event.

[Stefan]

Hello Jeff,

I am glad you find these articles useful.

As my colleagues Svett mentioned back in 2011, we were not able to replicate a case where the Scroll event will not be fired. I have just tested this again, with our latest version, and the event is triggered correctly.

Should you have any issues with this event, please get back to us with more details how to replicate the undesired behavior and we will gladly look into it.

Regards,
Stefan
Telerik