使用 AFMultipartFormData AFNetworking 3.0 上传图片

Image upload using AFMultipartFormData AFNetworking 3.0

NSURL *URL = [NSURL URLWithString:@"some APi"];

AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
manager.responseSerializer = [AFHTTPResponseSerializer serializer];

UIImage *myImageObj = [UIImage imageNamed:@"avatar.jpg"];
NSData *imageData= UIImagePNGRepresentation(myImageObj);

[manager POST:URL.absoluteString parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
    [formData appendPartWithFileData:imageData
                                name:@"file"
                            fileName:@"avatar.jpg" mimeType:@"image/jpeg"];

    // etc.
} progress:nil success:^(NSURLSessionDataTask *task, id responseObject) {
    NSLog(@"Response: %@", responseObject);
} failure:^(NSURLSessionDataTask *task, NSError *error) {
    NSLog(@"Error: %@", error);
}];

我正在尝试使用 afnetworking 3.0 上传图片,但每次都出现此错误

Domain=com.alamofire.error.serialization.response Code=-1011 "Request failed: internal server error (500)" UserInfo={com.alamofire.serialization.response.error.response= { URL: Some URL } { status code: 500, headers { "Access-Control-Allow-Origin" = "*"; "Content-Length" = 291; "Content-Type" = "text/html"; Date = "Thu, 26 Jan 2017 11:41:19 GMT"; Server = "Werkzeug/0.11.11 Python/2.7.12"; } },

幸运的是,邮递员提供了 objective-C 和一些其他语言的代码,但是对于 AFNetworking,我使用了这个

    NSURL *URL = [NSURL URLWithString:@"your URL"];

    UIImage *myImageObj = [UIImage imageNamed:@"image.jpg"];
    NSData *imageData= UIImageJPEGRepresentation(myImageObj, 0.6);

    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    //manager.responseSerializer=[AFJSONResponseSerializer serializer];
    manager.requestSerializer = [AFHTTPRequestSerializer serializer];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];

    [manager.requestSerializer setValue:@"multipart/form-data" forHTTPHeaderField:@"Content-Type"];

    [manager POST:URL.absoluteString parameters:nil constructingBodyWithBlock:^(id<AFMultipartFormData> formData) {
        [formData appendPartWithFileData:imageData
                                    name:@"file"
                                fileName:@"image.jpg" mimeType:@"image/jpeg"];

        // etc.
    } progress:nil success:^(NSURLSessionDataTask *task, id responseObject) {
        NSLog(@"Response: %@", responseObject);

        NSString *string = [[NSString alloc] initWithData:responseObject encoding:NSUTF8StringEncoding];
        NSLog(@"%@",string);

    } failure:^(NSURLSessionDataTask *task, NSError *error) {
        NSLog(@"Error: %@", error);
    }];