IOS选择器不执行

Question

@selector（apiRequest：didFinishWithData :)即使抓取器完成数据也不会执行。我试图用断点调试问题。当我在断点处循环时，我从选择器调用的方法不会被执行和绕过。这是因为选择器不在主线程上运行吗？我怎么能纠正这个？

   OADataFetcher *fetcher = [[OADataFetcher alloc] init];
   [fetcher fetchDataWithRequest:request
                        delegate:self
               didFinishSelector:@selector(apiRequest:didFinishWithData:)
                 didFailSelector:@selector(apiRequest:didFailWithError:)];



   (void)apiRequest:(OAServiceTicket *)ticket didFinishWithData:(NSData *)data {
   if (ticket.didSucceed) {
   NSString *responseBody = [[NSString alloc] initWithData:data
                                                  encoding:NSUTF8StringEncoding];
   NSLog(responseBody);
    //could use this to implement errors
   NSError* error;
   NSDictionary* json = [NSJSONSerialization
                         JSONObjectWithData:data //1
                         options:kNilOptions
                         error:&error];}
   }