CODEWITHSUNDEEP
iphoneuiviewcontroller
James
James

Reputation: 229

Where to put cleanup code in UIViewController?

I have a UIViewController subclass that loads a bunch of images for each cell in a tableview asynchronously which is handled by a separate download class. I keep a list of all of these download requests in a dictionary which is keyed to the index of the cell that is requesting the image.

My question is i where should i put the code that cancels the image download if the viewcontroller is popped off the navcontroller? I need to do this because if the user hits back while there are still images being downloaded (which could take a while) then when they are finished downloading the viewcontroller has already been released.

I cant put it in the viewWillDisappear method because i do not want to stop the download if the user clicks on a separate tab and only when the hit the back button. For now i put this code in the viewcontrollers dealloc method which works fine although it doesnt seem right for some reason. I thought of using the viewDidUnload method but it seems this is only called when there is a low memory warning?

Any ideas?

Upvotes: 1

Views: 1058

Answers (2)

Kendall Helmstetter Gelner
Kendall Helmstetter Gelner

Reputation: 75058

You may want to consider putting the code in viewWillDisappear: anyway, after all if the screen you are navigating to needs anything loaded it will be slowed by the background image load...

Upvotes: 0

JustSid
JustSid

Reputation: 25318

dealloc is the perfect place for this as the view controller gets deallocated and you are responsible to clean your stuff up.

Upvotes: 4

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