Appending rows in unbound mode is not supported in RadGrid. RadGrid items are generated only in respect to the data source it binds to. You can take an alternative approach for your scenario, though. Refer to the RadGrid Virtual Scrolling/Paging demo
and, in particular, to the second RadGrid example - Yahoo-style scrolling. Note how additional records are loaded to the grid when you scroll to the bottom of the master table. This example can be set up to work with client-side databinding.
You get very efficient loading of additional records by increasing the page size every time the user scrolls to the bottom. Becase you are using client-side databinding, no server round-trips are required as in the demo (where AJAX is used). And because you increase the page size by a constant amount every time, RadGrid needs to create only as many new rows as your constant (10 in the example). The previous rows are already created.
Attaching a sample test page to demonstrate this scenario. RadGrid is bound on the client to a page method returning 1000 items eventually.
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!