UIImageView+Asynchronous.m

@implementation UIImageView (Asynchronous)

+ (instancetype _Nonnull)imageViewWithURL:(NSString  * _Nonnull )url {
    return [self imageViewWithURL:url completionHandler:nil];
}

+ (instancetype _Nonnull)imageViewWithURL:(NSString  * _Nonnull )url
                        completionHandler:(completionHandler _Nullable)block {
    UIImageView *imageView = [UIImageView new];
    [imageView loadImageWithURL:url completionHandler:block];
    return imageView;
}

- (void)loadImageWithURL:(NSString *)url {
    [self loadImageWithURL:url completionHandler:nil];
}

- (void)loadImageWithURL:(NSString  * _Nonnull )url
       completionHandler:(completionHandler _Nullable)block {
    typeof(self) __weak weakSelf = self;
    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
    [[[NSURLSession sharedSession] dataTaskWithRequest:request
                                     completionHandler:^(NSData * _Nullable data,
                                                         NSURLResponse * _Nullable response,
                                                         NSError * _Nullable error) {
                                         dispatch_async(dispatch_get_main_queue(), ^{
                                             weakSelf.image = [UIImage imageWithData:data];
                                             if (block != nil) {
                                                 block(error);
                                             }
                                         });
                                     }] resume];
}

@end