标题:
Define与Const的使用(2)
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作者:
look_w
时间:
2019-3-7 19:27
标题:
Define与Const的使用(2)
结合经验,和在网上查找资料,我个人认为,可以得出以下结论:
多用类型常量,少用#define预处理指令(出自《Effective Objective-C》第四条原则)
2.苹果的API中,大多数字符串,也是用以下这种方式(如以Key,style,Type结尾的一些参数)
// Constants.h
FOUNDATION_EXPORT NSString *const MyFirstConstant;
FOUNDATION_EXPORT NSString *const MySecondConstant;
//etc.
// Constants.m
NSString *const MyFirstConstant = @"FirstConstant";
NSString *const MySecondConstant = @"SecondConstant";
或者
extern NSString * const PPRememberMusicList;
extern NSString * const PPLoadMusicAtListLoad;
extern NSString * const PPAfterPlayingMusic;
extern NSString * const PPGotoStartupAfterPlaying;
NSString * const PPRememberMusicList = @"Remember Music List";
NSString * const PPLoadMusicAtListLoad = @"Load music when loading list";
NSString * const PPAfterPlayingMusic = @"After playing music";
NSString * const PPGotoStartupAfterPlaying = @"Go to startup pos. after playing";
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