iphone - Need advice on speeding up tableViewCell photo loading performance -

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i have around 20 tableview cells each contain number (2-5) thumbnail sized pictures (they small facebook profile pictures, ex. http://profile.ak.fbcdn.net/hprofile-ak-sf2p/hs254.snc3/23133_201668_2989_q.jpg). each picture uiimageview added cell's contentview.

scrolling performance poor, , measuring draw time i've found uiimage rendering bottleneck.

i've researched/thought of solutions new iphone development not sure strategy pursue:

  • preload images , retrieve them disk instead of url when drawing cells (i'm not sure if cell drawing still slow, want hold off on time investment here)
  • have cells display placeholder image disk, while picture asynchronously loaded (this seems best solution, i'm not sure how best this)
  • there's fast drawing recommendation tweetie, don't know have affect if turns out overhead in network loading (http://blog.atebits.com/2008/12/fast-scrolling-in-tweetie-with-uitableview/)

thoughts/implementation advice? thanks!

suggest search in xcode docs lazytableimages. it's sample app provided apple asynchronously loads images table cell. should starting point.

you'll want add local cache save images don't have keep downloading them each time, , way prune out old images out of cache.


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