CODEWITHSUNDEEP
iphoneimagememoryuiscrollviewdidreceivememorywarning
Brian
Brian

Reputation: 819

iPhone Memory Warning Problems with UIScrollView

I am working on an iPad app that lets the user scroll through a number of images (usually around 20 .jpg files in a single horizontal scroll view). The file sizes are around 200 kb each. The images are set as the "Background" property of a UIButton because I wanted to allow the user to click the button to save the image. Every time I run the app, it crashes after scrolling for a little while. If you don't scroll, it behaves normal. I did run the app using the performance tools and didn't find any leaks.

I am getting a "Level=1" memory warning just before the app crashes. I had it running with about 8 images in the scrollview and never had a problem. So I know it has something to do with the scrollView and the images/buttons. In the "viewDidLoad" method, I simply did the following to set up the scrollView and then linked it in Interface Builder:

[scrollView setContentSize:CGSizeMake(5722, 340)];
[scrollView setScrollEnabled:YES];
[scrollView setDelaysContentTouches:YES];

Any ideas on how to get this to work? I added the images directly to the button in Interface Builder. Would it help if I deleted the background image, and instead set the backgrounds in the "viewDidLoad" method? Any help would be appreciated.

Upvotes: 2

Views: 1457

Answers (2)

dnaxxx
dnaxxx

Reputation: 175

as jer wrote, the problem seems to be in the recycling. Make sure to remove, release and update the content of each cell every time you get a new one in tableView:cellForRowAtIndexPath:

(I would have commented jer's post but I'm unable to do this, probably because of my limited permissions).

Upvotes: 0

jer
jer

Reputation: 20236

Sounds like what you need to do is create individual cells that these images live on, that get recycled like you'd get in a tableview. I have some code which does this that you may use for your purpose, or at least give it a go anyway. Works just like a tableview.

It's available here. This does the heavy lifting for you already, in that all you need to do is create one of these, slap it in a view somewhere, and create your individual cells. Those cells will be reused as you scroll so you won't need more than N + 2 cells loaded into memory at any one time, where N is the number that fit on your screen.

Upvotes: 1

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