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This question is very similar to this one, but there is no answer there, I cannot comment or do anything in that question and have a little different situation.

I have custom tableViewCell that has some custom View in it. This custom view contains UIImageView and UIActivityIndicatorView in it and also it has custom loader class attached to it. When this view first appears it's image is hidden and activityIndicator is animating, then loading process is launched (image is being loaded from some URL) and when image is successfully loaded it appears in my custom view. Everything works perfectly, but when I scroll by tableView very fast I have a lot of background NSURLConnections working in vain. I also created some methods to cancel my background connections, but I can't call them when I need it - there is no method being called when tableViewCell becomes off screen. I really need some event so I could cancel my background connections. Is there any way to do that? I really don't want to check if tableViewCell is still visible in every -connection:didReceiveData:, that's very lame but currently it seems like the only way to achieve what I need.

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DemoniacDeath
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1 Answers1

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My suggestion is to cancel your network request in your UITableViewCell's prepareForReuse: method. This is easy and also means that you won't cancel requests if the cell scrolls slightly off-screen and then back on. (You could also do this in tableView:cellForRowAtIndexPath: when you get back a cell to reuse.)

You might also want to look into avoiding starting those loads in the first place when scrolling fast; you could stop loading on scrollViewWillBeginDragging: and wait until, say, scrollViewDidEndDragging:willDecelerate: callback from the table view before starting the actual URL requests for the visible cells.

Jesse Rusak
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