[ios2]判断retina 屏幕

判断是否retina屏幕

#define isRetina ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].s

原文地址:https://www.cnblogs.com/jinjiantong/p/3356517.html