What are the best practices for using AJAX with DataGrids?

Question

I have a Data Grid and an Update Panel. Now, I was just looking over some blogs and found that you should use the least amount of Update Panels as you can. In my case, where I have a Datagrid and an Update Panel, which would be the best situation?

1) Keep the Datagrid inside the Update Panel.

2) Use an Update Panel inside ItemTemplates. So that only if I update only the selected row is updated not the whole grid.

Answer 1

If performance is your goal, start with the DataGrid. The amount of garbage it stores in viewstate is amazing.

UpdatePanel's in and of themselves aren't anywhere near as bad as a DataGrid.

Answer 2

Unfortunately, unless your DataGrid is very large, it won't make much difference either way.

The majority of your overhead is usually in reinstantiating the Page. Even if your UpdatePanel is only sending back one rendered row, the entire Page, including the entire DataGrid, must be re-created and rendered before the pertinent section of HTML can be extracted and sent back to the browser.

If what you have is working, I'd leave it alone and concentrate any ongoing efforts on a more client-centric approach, which is where huge performance gains are to be had.