Ajax & Large Listbox

[Jeremy]

I've got a very large listbox that gets populated using ajax. The listbox
and a button are in a panel inside an update panel. The button click of the
button sets the panel visible property to false. Everything works nice and
snappy except for when I click the button. The panel takes about 20 or so
seconds to dissapear. I think the ajax call has been made and the browser
is executing some javascript synchronously because the browser is blocking
and doesn't responde for those 20 or so seconds. My guess is the
javascriptis part of the ajax stuff because I didn't write any special
javascript to execute when the button is clicked. Does anybody know what
could be going on and how I can get rid of this slow response?

 

[Teemu Keiski]

Hi,

I think it's because with UpdatePanel the ViewState is posted also to the
server, so it's suffering because of that. How large us the ListBox, how
many items does it have? If you don't use UpdatePanel how long does it take
to make a full postback, does it also take that 20 seconds or more?

 

[Steve C. Orr [MCSD, MVP, CSM, ASP Insider]]

You might try making the panel invisible via JavaScript instead.
Something along these lines should do the trick:
MyPanel.style.display='none';