一直没用 main.storyboard, 后来索性把它删了,结果还出了问题:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Could not find a storyboard named 'Main' in bundle NSBundle </private/var/mobile/Containers/Bundle/Application/62378716-0423-4DC1-AF87-FF1BCE129EDB/Login With QQ.app> (loaded)'

有空再处理吧……