如何使用服务器上的AFNetworking上传视频

Question

我试图使用afnetworking上传视频，我的代码在下面作为回复它返回nil url如果你想要任何其他细节，请告诉我。我不知道我的错误在哪里。

{
        // add hud to show sending image
        [MBProgressHUD showHUDAddedTo:self.view animated:YES];


        NSString *format;
        format=@"video/mp4";

        myDict1 = @{@"user_id”:””,
                    @"timezone”:””,
                    @"friend_id”:””,
                    @"message_type”:””,
                    @"message":"",
                    @"language_id”:””
                    };

        AFHTTPSessionManager *manager=[AFHTTPSessionManager manager];
        NSString* webService=[NSString stringWithFormat:@"%@/send_messages",WEB_SERVICE_URL_BETA];

        [manager POST:webService parameters:myDict1 constructingBodyWithBlock:^(id<AFMultipartFormData>  _Nonnull formData)
         {
             [formData appendPartWithFileData:picturedata  name:@"file" fileName:@"testvideo.mov" mimeType:@"video/quickTime"];



                     } progress:nil success:^(NSURLSessionDataTask * Nonnull task, id  Nullable responseObject) {

             if ([[NSString stringWithFormat:@"%@",[responseObject valueForKey: @"status"] ] isEqualToString:@"1"])
             {

             }
             else
             {

             }
         }
              failure:^(NSURLSessionDataTask  _Nullable task, NSError  _Nonnull error) {
                  NSLog(@"Failure %@",error);
                               }];

          }