Question

Just wanted to know when using updatepanels if the whole page will be posted back or just the controls inside the updatepanel.

thanks

Answer 1

Using the UpdatePanel, the entire page is posted back (with the addition of a form value specifying that it is a partial page postback). Most of the page lifecycle still runs (PreRender is not, however, and render only renders the UpdatePanel and all children).

Only the UpdatePanel is rendered and sent back to the client, so it only modifies that portion of the page.