IOS判断Iphone5和Retina

#define isIPhone5 ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 1136), [[UIScreen mainScreen] currentMode].size) : NO)

#define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].size) : NO)

// 屏幕宽
#define SCREEN_WIDTH [[UIScreen mainScreen] bounds].size.width
// 屏幕高
#define SCREEN_HEIGHT [[UIScreen mainScreen] bounds].size.height