Xcode添加C语言代码出错

　　项目中须要用C语言实现一部分功能，新建C语言文件报错，错误以下：

　　检查C语言代码，并无什么写的不对的地方。查看错误信息列表，发现和本身代码相关的错误在.pch文件中。新建pch文件的时候，默认的是为整个项目代码引入UIkit、Foundation、CoreData框架，可是C语言文件中引入这些文件就会出错。因此这个时候，咱们把C语言文件隔离出来。

　　旧代码：

#ifndef iRun_Prefix_pch
#define iRun_Prefix_pch

// Include any system framework and library headers here that should be included in all compilation units.
// You will also need to set the Prefix Header build setting of one or more of your targets to reference this file.

#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
#import "Masonry.h"

#endif /* iRun_Prefix_pch */

　　新代码：

#ifdef __OBJC__
#define iRun_Prefix_pch

// Include any system framework and library headers here that should be included in all compilation units.
// You will also need to set the Prefix Header build setting of one or more of your targets to reference this file.

#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#import <CoreData/CoreData.h>
#import "Masonry.h"

#endif /* iRun_Prefix_pch */

　　以上。