sessiondownload

NSURLSessionDownloadTask *getImageTask = [session downloadTaskWithURL:[NSURL URLWithString:imageUrl]
                                                    completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {
                                                        // Here you use the location variable provided in the completion handler to get a pointer to the image
                                                        UIImage *downloadedImage = [UIImage imageWithData:[NSData dataWithContentsOfURL:location]];
                                                        // Finally you could, for example, update UIImageView’s image to show the new file.
                                                        dispatch_async(dispatch_get_main_queue(), ^{
                                                            // do stuff with image
                                                            _imageWithBlock.image = downloadedImage;
                                                        });
                                                    }];