拆分十六进制数

Question

新手问题。

比方说，我有十六进制数0xABCDEF，我怎么把它分成0xAB，0xCD和0xEF？ 是这样的吗？

unsigned int number = 0xABCDEF
unsigned int ef = a & 0x000011;
unsigned int cd = (a>>8) & 0x000011;
unsigned int ab = (a>>16) & 0x000011;

由于

Answer 1

使用0xff作为掩码删除除数字8位以外的所有内容：

unsigned int number = 0xABCDEF
unsigned int ef = number & 0xff;
unsigned int cd = (number>>8) & 0xff;
unsigned int ab = (number>>16) & 0xff;

Answer 2

unsigned int number = 0xABCDEF
unsigned int ef = number & 0xff;
unsigned int cd = (number >> 8) & 0xff;
unsigned int ab = (number >> 16) & 0xff;

而不是按位和（&）操作，您可能希望ef，cd，ab为unsigned char类型，具体取决于其余代码以及您如何使用这些变量。在这种情况下，您转为unsigned char：

unsigned int number = 0xABCDEF
unsigned char ef = (unsigned char) number;
unsigned char cd = (unsigned char) (number >> 8);
unsigned char ab = (unsigned char) (number >> 16);

Answer 3

要使用的掩码为0xFF，而不是0x11。除此之外，你是对的。

Answer 4

void splitByte(unsigned char * split, unsigned int a,int quantBytes)
{
  unsigned char aux;
  int i;
  for(i=0;i<quantBytes;i++)
  {
      split[i]=a&0x00FF; 
      a=(a>>8);
  }
  for(i=0;i<quantBytes-1;i++)
  {
      aux = split[i];
      split[i] = split[quantBytes-i-1];
      split[quantBytes-i-1] = aux;

  }
}

主要： unsigned char split [4]; splitByte（split，0xffffffff，4）;