.net - how to prevent user controls code behind running in async postbacks? -

i have aspx page contains dozens of custom controls issue have asp.net ajax update panel update small area of page other user controls lives in page.(user controls outside update panel , update panel has updatemode="conditional") there way of programatically prevent running code behind of custom controls, since seriosly degrade performace/page load time. have check isasyncpostback script manager prevent unnecessary calls dal. there way prevent running custom control code behind according following conditions,

• cannot touch custom control code behind,ascx page file etc
• cannot use caching
• any change can done aspx page , code behind referring above.
• cannot integrate jquery or javascript frameworks(wish could) late now.

slightly off-topic, have freedom explore methods not include use of updatepanel? known have poor performance , should used sparingly.

with said, page lifecycle methods usercontrols must fire them rendered again. updatepanel methodology isn't expect "ajax" solution, because technically when updatepanel updates entire page re-rendered, parts asked change returned , redrawn in ui.

what might able check if you're in middle of ajax postback via:

scriptmanager.isinasyncpostback 

then can prevent code running in usercontrol's methods if property evaluates true.