OpenUrl freezes app for over 10 seconds

[[UIApplication sharedApplication] openURL:urlString] 메소드 사용시 10초 이상 프리징 되는 현상이 발생함.

딜레이도 아니고 프리징.. 10초 정도 아무것도 안됨..

아래 세 가지 방법으로 해결..

어쨌든 해결되는 원리는 같겠지만 ㅋㅋ

#1. 메인 쓰레드 호출해서 실행

dispatch_async(dispatch_get_main_queue(), ^{
    [[UIApplication sharedApplication] openURL:urlString];
});

#2. performSelector 메소드 실행

- (void)applicationDidBecomeActive:(UIApplication *)application
{
  ...

  //hangs for 10 seconds
  //[[UIApplication sharedApplication] openURL:[NSURL URLWithString: url]];

  //Fix: use threads!
  [self performSelector:@selector(redirectToURL:)
      withObject:url afterDelay:0.0];

  ...
}

- (void)redirectToURL:(NSString *)url
{
  [[UIApplication sharedApplication] openURL:[NSURL URLWithString: url]];
}

#3. NSThread 이용

- (void)applicationDidBecomeActive:(UIApplication *)application
{
  ...

  //hangs for 10 seconds
  //[[UIApplication sharedApplication] openURL:[NSURL URLWithString: url]];

  //Fix: use threads!
  [NSThread detachNewThreadSelector:@selector(openBrowserInBackground:)
      toTarget:self withObject:url];

  ...
}

- (void)openBrowserInBackground:(NSString *)url
{
  [[UIApplication sharedApplication] openURL:[NSURL URLWithString: url]];
}

[출처] http://stackoverflow.com/questions/19356488/openurl-freezes-app-for-over-10-seconds