how do sharepoint pages load?

Question

I need to understand the load sequence for a sharepoint page that uses a query string to filter content.

If I pass in a query string, I assume that SharePoint first passes that query string to any web parts that need it, waits for the web parts to load their content then loads the final page? OR does SharePoint first load the page then pass the query to its web parts.

Answer 1

The QueryString is acessible in your webparts, it gets passed at the very beginning of the request.

Answer 2

Web Part is just another Control in the Page and it behaves in the same way as other controls, so same Page Execution Cycle happens in the WebPart pages as well and the Query String will be always avaliable in your WebPart code.