DataGrid paging with persistent data

Question

In a Sharepoint web part, I have a DataGrid with paging that I load with all of the data (not using custom paging - custom paging would require a significant overhaul in the current process and is probably one of the last options I can try). I was wondering if it was possible to have it page through the data without re-binding the data source to the grid in the page index changed event? If I remove my current calls to re-bind the data, it remains on the first page no matter what.

Answer 1

With a datagrid, I think you need to re-bind the grid whenever you want to go to a new page.

"A typical handler for the PageIndexChanged event sets the CurrentPageIndex property to the index of the page you want to display and then uses the DataBind method to bind the data to the DataGrid control."

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.datagrid.onpageindexchanged%28VS.71%29.aspx

If you want to avoid querying/fetching the data over again from the source, then you'll need to "cache" the data between postbacks. There are various options here, each with it's own advantages and drawbacks.

If the size of the data is not too large and is not sensitive, you can simply put the data in viewstate on the first page load, and read it out again when the page index is changed. Another option might include using Session to "cache" the data, although this can get tricky if not done right, and of course there will be more load on the server side with this method (with varying amounts, depending on if the Session is In-Proc, State Server, or Database). There may be other methods to "cache" the data, but that is what you'd need to do in this case.