ios - 如何知道 AfNetworking 是否下载了所有图像

Question

我想我问的是一个愚蠢的问题，但只是好奇。有什么方法可以知道是否所有图像都已下载。我这样做的动机是，我想在下载完所有图像后调用一个函数。

我在 for 循环中使用 UIImageview setImageWithURL

提前致谢:)

Answer 1

您需要使用 UIImageView+AFNetworking 的 setImageWithURLRequest 方法。成功 block 在图像加载完成时执行。

 @param urlRequest The URL request used for the image request.
 @param placeholderImage The image to be set initially, until the image request finishes. If `nil`, the image view will not change its image until the image request finishes.
 @param success A block to be executed when the image request operation finishes successfully. This block has no return value and takes three arguments: the request sent from the client, the response received from the server, and the image created from the response data of request. If the image was returned from cache, the request and response parameters will be `nil`.
 @param failure A block object to be executed when the image request operation finishes unsuccessfully, or that finishes successfully. This block has no return value and takes three arguments: the request sent from the client, the response received from the server, and the error object describing the network or parsing error that occurred.
 */
- (void)setImageWithURLRequest:(NSURLRequest *)urlRequest
              placeholderImage:(UIImage *)placeholderImage
                       success:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image))success
                       failure:(void (^)(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error))failure;