performSegueWithIdentifier not automatically jump

In viewDidLoad to call performSegueWithIdentifier, connection set too no problem, but can not automatically jump to another VIEW, whereas no problem using the trigger button, who can solve it?
Reply:
After testing can not seem to put in viewDidLoad. Add viewDidAppear no problem

Reply:
viewDidLoad not deal with things on
UI interfaceOnly viewDidAppear only appeared after the UI interface to handle!