SDWebImagePrefetcher

SDWebImagePrefetcher

SDWebImagePrefetcher *prefetcher = [SDWebImagePrefetcher sharedImagePrefetcher];
[prefetcher prefetchURLs:_arrayNSURL progress:nil completed:^(NSUInteger completedNo, NSUInteger skippedNo) {
    // Added a quick fix for getting the image from cache immediately(null error).
 [self performSelector:@selector(createScrollViewContent) withObject:nil afterDelay:0.25];
}];

SDImageCache

// Get a image from SDImageCache.
SDImageCache *cache = [SDImageCache sharedImageCache];
UIImage *resizeImage = [UIImage resizeImage:[cache imageFromDiskCacheForKey:[item.picUrl absoluteString]] convertToWidth:300];
UIImageView *imageView = [[UIImageView alloc] initWithImage:resizeImage];
imageView.contentMode = UIViewContentModeTopLeft;
imageView.clipsToBounds = YES;