ios - IOS 选择器不执行

Question

@selector(apiRequest:didFinishWithData:) 不会执行，即使 fetcher 确实完成了数据。我试图用断点调试问题。当我循环通过断点时，我从选择器调用的方法没有被执行和绕过。这是因为选择器不在主线程上运行吗？我该如何纠正？

   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];}
   }