Question

我写的照片查看应用程序有问题。

我有一个内置UINavigationController的UITabBarController。 UINavigationController最初显示UITableView。在选择时，它会推送另一个UIViewController（个人相册）以及一张NSArray照片。这个Controller包含一个UIScrollView / UIPageControl，它显示了几个UIVmageControllers，其中有一个UIImageView。

该应用程序最初效果很好。它为每个相册正确加载每个图像，您可以从导航栏返回。问题是在大约180张图像之后，应用程序开始抛出内存警告并最终崩溃抛出“程序接收信号：”0“。警告：check_safe_call：无法恢复当前帧”我认为这与低内存有关。令人难以置信的是令人沮丧，因为我已经检查过并且没有泄漏，并且每个dealloc都被调用。 dealloc方法释放每个保留的属性并将它们设置为nil。

如果你签入了仪器，它会显示每张专辑被查看后内存使用量逐渐增加。它确实释放了一些内存，但不是全部。例如如果专辑使用1MB显示0.9MB可能会被释放。

任何帮助将不胜感激。这是我发布之前的最后一个问题。

编辑：这是基本项目文件的链接。 http://www.mediafire.com/?nztrd1yhzoo

AlbumsViewController（推送个人“albumviewcontroller”）

 - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

 NSMutableDictionary *dictThisItem = [self.arrAlbums objectAtIndex:[indexPath row]];
    NSString *strBand = [dictThisItem objectForKey:@"album"];

  NSMutableArray *arrThesePhotos = [[self.arrAlbums objectAtIndex:[indexPath row]] objectForKey:@"photos"];

  if (self.albumViewController == nil){
   self.albumViewController = [[AlbumViewController alloc] initWithNibName:nil bundle:nil];
  }
  albumViewController.hidesBottomBarWhenPushed = YES;
  [self.navigationController pushViewController:albumViewController animated:YES];
  self.albumViewController.arrPhotos = arrThesePhotos;
  [albumViewController populateScroller];
}

AlbumViewController

- (void)populateScroller {

imagesScroller.pagingEnabled = YES;
imagesScroller.contentSize = CGSizeMake(imagesScroller.frame.size.width * [self.arrPhotos count], 380);
imagesScroller.showsHorizontalScrollIndicator = NO;
imagesScroller.showsVerticalScrollIndicator = NO;
imagesScroller.scrollsToTop = NO;
imagesScroller.delegate = self;
imagesScroller.backgroundColor = [UIColor blackColor];
[imagesScroller scrollRectToVisible:CGRectMake(0.0, 0.0, 320.0, 480.0) animated:NO];

pageControl.numberOfPages = [self.arrPhotos count];
pageControl.currentPage = 0;
 pageControl.backgroundColor = [UIColor blackColor];



 NSMutableArray *controllers = [[NSMutableArray alloc] init];
for (int i = 0; i < [self.arrPhotos count]; i++) {

  CGRect frame = imagesScroller.frame;
    frame.origin.x = frame.size.width * i;
    frame.origin.y = 0;

  NSString *strImagePath = [[self.arrPhotos objectAtIndex:i] stringByReplacingOccurrencesOfString:@"iPhone" withString:@"iPhone_thumbnail"];

  ImageViewController *imageViewController = [ImageViewController alloc];
  imageViewController.localImage = YES;
  imageViewController.albumViewController = self;
  [imageViewController initWithPhotoName:strImagePath];
  [controllers addObject:imageViewController];

  imageViewController.view.frame = frame;
  [imagesScroller addSubview:imageViewController.view];

  [imageViewController release];

}
self.viewControllers = controllers;
[controllers release];

}

ImageViewController

- (void)viewDidLoad {

 self.navigationShown = NO;

 Cache *cache = [[Cache alloc] init];
 [cache release];


 NSString *strURL = [@"http://www.marklatham.co.uk" stringByAppendingString:self.strThisPhoto];
 NSString *strTmpPrefix = (self.localImage) ? @"_tmp_rockphotothumb_" : @"_tmp_rockphotolarge_";

// Cache Paths
NSArray *arrPaths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
NSString *strLocalPath = [[arrPaths objectAtIndex:0] stringByAppendingString:@"/"];
NSString *strPrefix = (strTmpPrefix != nil) ? strTmpPrefix : @"_tmp_rockphotolarge_";

NSMutableArray *arrImagePaths = (NSMutableArray *)[strURL componentsSeparatedByString:@"/"];


// Check cache
NSString *strEntireLocalCache = [strLocalPath stringByAppendingString:[strPrefix stringByAppendingString:[arrImagePaths objectAtIndex:[arrImagePaths count]-1]]];
if ([[NSFileManager defaultManager] fileExistsAtPath:strEntireLocalCache]){

    UIImageView *imvImageView = [UIImageView alloc];
    UIImage *image = [[UIImage imageWithContentsOfFile:strEntireLocalCache] autorelease]; 
    [imvImageView initWithImage:image];

    CGSize imgSize = image.size;
    CGFloat fltWidth = imgSize.width;
    CGFloat fltHeight = imgSize.height;

    // If landscape rotate image
    if (fltWidth > fltHeight){
        imvImageView.frame = CGRectMake(-80.0, 80.0, 481.0, 320.0);

        CGAffineTransform rotate = CGAffineTransformMakeRotation(-1.57079633);
        [imvImageView setTransform:rotate];
    }else{
        imvImageView.frame = CGRectMake(0.0, 0.0, 320.0, 481.0);
    }

    [self.view addSubview:imvImageView];
    [imvImageView release];

}else{

    // Data URL Downloading
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
    NSData *datImageData = [NSData dataWithContentsOfURL: [NSURL URLWithString:strURL]];
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];

    [datImageData writeToFile:strEntireLocalCache atomically:YES];

    UIImageView *imvImageView = [UIImageView alloc];
    UIImage *image = [[UIImage imageWithData: datImageData] autorelease];
    [imvImageView initWithImage:image];

    CGSize imgSize = image.size;
    CGFloat fltWidth = imgSize.width;
    CGFloat fltHeight = imgSize.height;

    // If landscape rotate image
    if (fltWidth > fltHeight){
        imvImageView.frame = CGRectMake(-80.0, 80.0, 481.0, 320.0);

        CGAffineTransform rotate = CGAffineTransformMakeRotation(-1.57079633);
        [imvImageView setTransform:rotate];
    }else{
        imvImageView.frame = CGRectMake(0.0, 0.0, 320.0, 481.0);
    }

    [self.view addSubview:imvImageView];
    [imvImageView release];

}

}

Answer 1

正确使用ObjectAlloc仪器，您可以准确找到正在使用的内存的位置，从而找出内存泄漏的原因。

Answer 2

确保使用仪器并检查泄漏视图。

但是，如果您确定它没有泄漏：如果您加载较少的图像，这个问题是否需要更长的时间？您可能希望尝试对图像进行下采样，以便更多地适合内存，或者仅在需要时从磁盘加载它们。

另外，在这一行：

UIImage *image = [[UIImage imageWithContentsOfFile:strEntireLocalCache] autorelease];

我认为autorelease调用是不必要的，因为方法名称idiom +objectWithArgument:会返回一个自动释放的对象。我不确定自动释放两次是否会在以后产生不良后果，但值得一试。尝试解决这个问题，看看是否有任何变化。

Answer 3

在说服我的客户之后，我设法通过使用three20框架来解决这个问题。

UIScrollView中的几个UIImageViews和崩溃

3 个答案: