NSNetServiceBrowser cannot find any service, the delegate method does not seems to be called

问题

I am using NSNetServiceBrowser to browse bonjour service. The service is started successfully, however, I am facing an issue while browsing the service. When I make the call searchForServicesOfType:inDomain, only the netServiceBrowserWillSearch delegate method is called. No other delegate method is called and I cant find any service. The answer seems to be given by this guy here, NSNetServiceBrowser not finding services that exist but I cant understand what does he actually means (see part 2 of the answer). The author of the question solved the problem but he didnt elaborated. Please tell me why the other delegate methods like netServiceBrowser:didFindService:moreComing: are not called Thanks in anticipation.

来源：https://stackoverflow.com/questions/14479434/nsnetservicebrowser-cannot-find-any-service-the-delegate-method-does-not-seems