在arm64上使用NSScanner处理CGFloat [英] Handling CGFloat with an NSScanner on arm64
本文介绍了在arm64上使用NSScanner处理CGFloat的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
显然 CGFloat
在arm64上是 double
Apparently CGFloat
is double
on arm64:
#if defined(__LP64__) && __LP64__
# define CGFLOAT_TYPE double
# define CGFLOAT_IS_DOUBLE 1
# define CGFLOAT_MIN DBL_MIN
# define CGFLOAT_MAX DBL_MAX
#else
# define CGFLOAT_TYPE float
# define CGFLOAT_IS_DOUBLE 0
# define CGFLOAT_MIN FLT_MIN
# define CGFLOAT_MAX FLT_MAX
#endif
所以代码
NSScanner *scanner = [NSScanner scannerWithString:string];
CGFloat c[components];
[scanner scanFloat:&c[i]]
位应用程序,64位已损坏。它可以替换为
which was working fine for 32-bit apps, is broken for 64-bit. It can be replaced with
NSScanner *scanner = [NSScanner scannerWithString:string];
CGFloat c[components];
#if CGFLOAT_IS_DOUBLE
[scanner scanDouble:&c[i]];
#else
[scanner scanFloat:&c[i]];
#endif
但是有更好的选择吗?
推荐答案
NSScanner
仅支持一些基本类型,所以你需要在某个地方使用#if指令。也就是说,如果您经常使用这种方式,您可以继承NSScanner或使用类别,使代码更加优雅。
NSScanner
only supports a few basic types, so you're going to need to have that #if directive somewhere. That said, if you're using this often you could subclass NSScanner or use a category to make the code more elegant.
我认为基于类别的代码看起来像:
I think the category-based code would look something like:
NSScanner + MyAdditions.h:
NSScanner+MyAdditions.h:
#import "NSScanner.h"
@interface NSScanner (MyAdditions)
- (BOOL)my_scanCGFloat:(CGFloat *) cgFloatValue
@end
NSScanner + MyAdditions.m:
NSScanner+MyAdditions.m:
#import "NSScanner+MyAdditions.h"
@implementation NSScanner (MyAdditions)
- (BOOL)my_scanCGFloat:(CGFloat *) cgFloatValue {
#if CGFLOAT_IS_DOUBLE
return [self scanDouble:cgFloatValue];
#else
return [self scanFloat:cgFloatValue];
#endif
}
@end
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