Question

我正在做一个像相册一样的iPad应用程序，我使用带分页的UIScrollView来显示照片图像。我的问题是应用程序在模拟器中运行完美，但在查看大约50张照片后会崩溃。我在泄漏测试中测试它，内存不断增加，我不知道在哪里，以及哪个项目需要释放。我还将加载图像编码更改为“imageWithContentsOfFile”以避免在缓存上加载图像。

我的应用程序包括3个类：AppDelegate，viewController和DetailViewController。 viewController的nib有一个UIScrollView，DetailViewController nid包含UIImageView。

//viewController.m

static NSUInteger kNumberOfPages = 0;

@interface ScrollViewPagingLandscapeViewController (PrivateMethods)

- (void)loadScrollViewWithPage:(int)page;
- (void)scrollViewDidScroll:(UIScrollView *)sender;

@end

- (void)viewDidLoad {
    [super viewDidLoad];
kNumberOfPages = [photosArray count];

NSMutableArray *controllers = [[NSMutableArray alloc] init];
for (unsigned i = 0; i < kNumberOfPages; i++) {
    [controllers addObject:[NSNull null]];
}
self.viewControllers = controllers;
[controllers release];

// a page is the width of the scroll view
scrollView.pagingEnabled = YES;
scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * kNumberOfPages, scrollView.frame.size.height);
scrollView.showsHorizontalScrollIndicator = NO;
scrollView.showsVerticalScrollIndicator = NO;
scrollView.scrollsToTop = NO;
scrollView.delegate = self;
pageControl.numberOfPages = kNumberOfPages;
pageControl.currentPage = 0;
// pages are created on demand
// load the visible page
// load the page on either side to avoid flashes when the user starts scrolling
[self loadScrollViewWithPage:page];
[self loadScrollViewWithPage:page + 1];
}

- (void)loadScrollViewWithPage:(int)page {
if (page < 0) return;
if (page >= kNumberOfPages) return;

// replace the placeholder if necessary
DetailViewController *controller = [viewControllers objectAtIndex:page];
if ((NSNull *)controller == [NSNull null]) {
    controller = [[DetailViewController alloc] initWithPageNumber:page];
    [viewControllers replaceObjectAtIndex:page withObject:controller];
    [controller release];
}

// add the controller's view to the scroll view
    if (nil == controller.view.superview) {
        CGRect frame = scrollView.frame;
        frame.origin.x = frame.size.width * page;
        frame.origin.y = 0;
        controller.view.frame = frame;
        [scrollView addSubview:controller.view];
    }
}

- (void)scrollViewDidScroll:(UIScrollView *)sender {


// Switch the indicator when more than 50% of the previous/next page is visible
CGFloat pageWidth = scrollView.frame.size.width;
int page = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
pageControl.currentPage = page;

// load the visible page and the page on either side of it (to avoid flashes when the user starts scrolling)
[self loadScrollViewWithPage:page - 1];
[self loadScrollViewWithPage:page];
[self loadScrollViewWithPage:page + 1];

// A possible optimization would be to unload the views+controllers which are no longer visible
}

- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
self.scrollView = nil;
self.viewControllers = nil;
self.totalpage = nil;

}

- (void)dealloc {
[scrollView release];
[viewControllers release];
[totalpage release];
    [super dealloc];
}

// DetailViewController.m

- (id)initWithPageNumber:(int)page {
     if (self = [super initWithNibName:@"DetailViewController" bundle:nil]) {
        pageNumber = page;
     }
     return self;
}

- (void)dealloc {

    [imageView release];
    [super dealloc];
}


- (void)viewDidLoad {
  NSBundle *bundle = [NSBundle mainBundle];
  NSString *imagePath = [bundle pathForResource:[[photosArray objectAtIndex:pageNumber] objectForKey:@"imageName"] ofType:@"jpg"];
  UIImage *tempImage = [UIImage imageWithContentsOfFile:imagePath];
  imageView.image= tempImage;

}

这是我第一次提问，请提醒我，如果我错过了什么。还要感谢回答我的问题。

UIScrollView在ipad中模拟器崩溃时查看图像很好

0 个答案: