couldnotbuildmodule‘Foundation’,couldnotbuildmodule‘UIKit’……23个错误

pch文件加入

#import<Availability.h>

#ifndef __ipHONE_3_0

#warning "ThisPRoject uses features only available in iOS SDK 3.0 and later."

#endif

#ifdef __OBJC__

#import<UIKit/UIKit.h>

#import<Foundation/Foundation.h>