I once saw this feature in action but I don't know how to turn it on. The grid can show a tooltip with the current row number (or row ID) while dragging the scrollbar. This helps you to stop the scroll in the right place. I'm assuming some property will turn this on, but I can't find it. Maybe it is also dependent on the scroll mode?
UPDATE: In the image below you can see an example of the tooltip I'm looking for. This is displayed while the scrollbar is being dragged (up or down). The number in the tooltip is the row number (you can't see it in this image, way to the left in the grid). This is the same grid that I am using now. Just from a very old build of our product. Somehow this tooltip was turned off. And no one knows how to turn it back on :( I'm pretty sure this is a built in feature of the ultrawebgrid. Not something that required extra coding.
alt text http://img138.imageshack.us/img138/6337/croppercapture.jpg
Right! Now that we've established that you have version 6.3, I've hopefully got a solution for you. I don't have 6.3 myself, but I've got a slightly later one that I think didn't have Virtual Scrolling added as a feature yet.
So try this code:
webgrid.DisplayLayout.XmlLoadOnDemandType = XmlLoadOnDemandType.Virtual;
This should automatically put a tooltip on the grid as you scroll down. Have a look here for a running sample... (and remember to choose the virtual option)
Here's hoping!
Rob G