site_archiver@lists.apple.com Delivered-To: cocoa-dev@lists.apple.com There's some good information on this in TechNote 2009 <http://developer.apple.com/library/ios/#technotes/tn2009/tn2109.html> Also, here is some sample code you might find very helpful: <http://developer.apple.com/library/mac/#samplecode/LinkedImageFetcher/> as it does almost what you're describing. HTH, -Steve Hi Stephen, Thanks for your reply, so there is no any perfect solution for this kind of problem? And can you give me a specific example to demonstrate why why it is not safe to release these async objects inside a callback method and why not safe to autorelease it? Thanks. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/site_archiver%40lists.apple... At 5:28 PM +0800 12/28/10, ico wrote: This email sent to site_archiver@lists.apple.com