Prefix.pch文件-判断iOS系统版本

ItcastWeibo-Prefix.pch

//
//  Prefix header
//
//  The contents of this file are implicitly included at the beginning of every source file.
//

#import <Availability.h>

#ifndef __IPHONE_5_0
#warning "This project uses features only available in iOS SDK 5.0 and later."
#endif

#ifdef __OBJC__
    #import <UIKit/UIKit.h>
    #import <Foundation/Foundation.h>
    #define iOS7 ([[[UIDevice currentDevice] systemVersion]doubleValue] >= 7.0)
#endif

Prefix.pch文件-判断iOS系统版本

原文：http://www.cnblogs.com/xiaokanfengyu/p/4052142.html