objective-c - ARC 问题 : No known instance method for selector 'appendPartWithFileData:mimeType:name:'

Question

按照 AFNetworking 示例上传表单时:

NSURL *url = [NSURL URLWithString:@"https://www.example.com/"];
AFHTTPClient *client = [[AFHTTPClient alloc] initWithBaseURL:url];

NSDictionary *params = [NSDictionary dictionaryWithObjectsAndKeys:
                        keyField.text, @"key",
                        valField.text, @"val",
                        nil];

NSData *imageData = UIImagePNGRepresentation(image);

NSURLRequest *request = [client multipartFormRequestWithMethod:@"POST" 
                                                          path:@"/upload" 
                                                    parameters:params 
                                     constructingBodyWithBlock: ^(id <AFMultipartFormData> formData) {
                                         [formData appendPartWithFileData:imageData 
                                                                 mimeType:@"image/png" 
                                                                     name:@"avatar"];
                                     }];

编译返回错误:

ARC Issue: No known instance method for selector 'appendPartWithFileData:mimeType:name:'

我该如何解决？

Answer 1

编译器将此视为“ARC 问题”有点奇怪。恕我直言，AFMultipartFormData 协议(protocol)不包含名为 appendPartWithFileData:mimeType:name: 的方法。看看文档，也许协议(protocol)被重构了，方法签名也发生了一些变化。我不确定 AFMultipartFormData 从哪里来，但简短的搜索给了我 these docs这表明您可能会成功使用 appendPartWithFileData:name:fileName:mimeType:。