UITableView with image in cell stucks - ios

Question

I am developing an app which use UITableView,which contains cell having UIImageView of size 320 X 200.
This images comes from the web url and store to my app folder.Then i am showing this image to user.
For that i am using "UIImageView+AFNetworking.h" class's below method.
- (void)setImageWithURL:(NSString *)url
placeholderImageName:(NSString *)placeholderImage
saveFilePath:(NSString *) filePath
IndexPath:(NSIndexPath *)indexPath
success:(void (^)(NSIndexPath *indexPath, UIImage *image))success
failure:(void (^)(NSIndexPath *indexPath, NSError *error))failure {
NSLog(#"DOWNLOAD IMG URL :: %#", url);
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]];
[request setHTTPShouldHandleCookies:NO];
[request setHTTPShouldUsePipelining:YES];
[request addValue:#"image/*" forHTTPHeaderField:#"Accept"];
[self setImageWithURLRequest:request
placeholderImage:placeholderImage == nil? nil : [UIImage imageNamed:placeholderImage]
success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image) {
[Storage SaveImage:image WithFileName:filePath];
if (success)
success(indexPath, image);
}
failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {
if (failure)
failure(indexPath, error);
}
];
}
when my all images downloaded to my local folder after that my tableview stucks while showing images.

Answer 1

It might be possible that the downloading happens in sync with the main thread and is blocking it until the download has finished.
I use SDWebImage in my projects for this. It work's really really well.
EDIT:
OK, AFNetworking is doing all the work asynchronously and also caches all the images. See the documentation.
If you don't need your success and failure blocks, you could go away with this.
- (void)setImageWithURL:(NSString *)url
placeholderImageName:(NSString *)placeholderImage {
NSURL *url = [NSURL URLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
UIImage *pImage = placeholderImage == nil? nil : [UIImage imageNamed:placeholderImage];
[self setImageWithURL:url placeholderImage:pImage];
}

Answer 2

Or maybe the image is extremely large (that's independent of the UIImageView size).
Can we see your code?
Do you load them manualy from the file system? Probably is that, because you do that in the main thread.
Try this in the code that loads the image:
NSLog(#"Is this the main thread: %d", [NSThread isMainThread]);
If you see 1, that's the problem. You can solve it using GCD (remember that once the image is loaded, move it to the main thread)

Answer 3

Use NSOperationQueue for downloading image. While adding new item in NSOperationQueue, first check if it already added or not.
After NSOperation complete, that image will save into local.
Always load image from locally. If image not present in local then display some place holder.
Hope it helps.
Regards,
Punita