ios - NSUInteger 字符串编码 32 位和 64 位

Question

我正在尝试找出将 NSUInteger 转换为适用于 32 位和 64 位系统的字符串的最佳方法。我看到两个平台的 NSUInteger 定义不同，我想确保我所做的是正确的。

我见过的所有解决方案都需要一些转换，或者看起来不正确。我收到以下代码的警告，要求我添加显式强制转换。

NSUInteger unsignedInteger = PostStatusFailed; // This is an enum
NSString *string = [NSString stringWithFormat:@"postStatus == %lu", unsignedInteger];

我也尝试过 %d(有符号整数，这似乎不正确)和 %lx，但似乎都不正确。谢谢。

Answer 1

来自String Programming Guide :

OS X uses several data types—NSInteger, NSUInteger,CGFloat, and CFIndex—to provide a consistent means of representing values in 32- and 64-bit environments. In a 32-bit environment, NSInteger and NSUInteger are defined as int and unsigned int, respectively. In 64-bit environments, NSInteger and NSUInteger are defined as long and unsigned long, respectively. To avoid the need to use different printf-style type specifiers depending on the platform, you can use the specifiers shown in Table 3. Note that in some cases you may have to cast the value.

查看所有类型的链接。对于NSUInteger，正确的做法是:

NSUInteger i = 42;
NSString *numberString = [NSString stringWithFormat:@"%lu is the answer to life, the universe, and everything.", (unsigned long)i];