引入了这个头文件<QuartzCore/CoreAnimation.h>

/* QuartzCore.h

   Copyright (c) 2004-2016, Apple Inc.
   All rights reserved. */

#ifndef QUARTZCORE_H
#define QUARTZCORE_H

// 引入了这个头文件 
#include <QuartzCore/CoreAnimation.h>

#endif /* QUARTZCORE_H */