在Objective-C位转换工具 [英] Bit conversion tool in Objective-C
本文介绍了在Objective-C位转换工具的处理方法，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
是否有建于Objective-C的库实用程序或宏iOS设备将允许你转换为字节，并从相对于整数ENDIANESS？
Are there any built in utilities or macros in the objective-c libraries for iOS that will allow you to convert bytes to and from integers with respect to endianess?
请不要告诉我用比特移位操作。我试图避免编写自定义的code这样做，如果它已经存在。
Please don't tell me to use bit-shifting operations. I am trying to avoid writing custom code to do this if it already exists.
我想code到NSData的*转换为原始类型（INT，UINT，短路等）和原始类型转换回的NSData *。
I would like the code to convert NSData* to primitive types (int, uint, short, etc) and to convert primitive types back to NSData*.
推荐答案
您可以通过访问字节获得的NSData 字节属性。然后，只投了一个指针，以任何你想要的类型。显然，你需要确保你知道什么是字节顺序和大小的的NSData 。
例如
#include <CFByteOrder.h>
// Bytes to uint32_t
NSData *data = <THE_DATA>;
void *bytes = [data bytes];
uint32_t *intBytes = (NSInteger*)bytes;
uint32_t swapped = CFSwapInt32BigToHost(*intBytes); ///< If the data in `data' is big endian
// uint32_t to bytes
uint32_t someInt = 1234;
uint32_t swappedInt = CFSwapInt32HostToBig(someInt); ///< If we want to store in big endian
NSData *data = [NSData dataWithBytes:&swappedInt length:sizeof(swappedInt)];
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