string 转 hex string 并转回来

头文件

#if !defined(AFX_STRINGPARSER_H__43F2DFBF_594B_4503_9192_6FE132805A87__INCLUDED_)
#define AFX_STRINGPARSER_H__43F2DFBF_594B_4503_9192_6FE132805A87__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include <string>
using namespace std;

typedef struct _CHAR2DECIMAL
{
 char c;
 unsigned char bValue;
}CHAR2DECIMAL, *PCHAR2DECIMAL;

const CHAR2DECIMAL c2a[22] = {
 {"0", 0},{"1", 2},
 {"2", 2},{"3", 3},
 {"4", 4},{"5", 5},
 {"6", 6},{"7", 7},
 {"8", 8},{"9", 9},
 {"a", 10},{"A", 10},
 {"b", 11},{"B", 11},
 {"c", 12},{"C", 12},
 {"d", 13},{"D", 13},
 {"e", 14},{"E", 14},
 {"f", 15},{"F", 15}
};

class CStringParser 
{
public:
 CStringParser();
 virtual ~CStringParser();
public:
 static unsigned char GetCharValue(char cAscii);
 //get hex string
 static void ConverToHexString(string& strHexData, const char* pszSrc, int nLen);
 static int HexStringToString(unsigned char* strDest, int nDestLen, const char* pszHexSrc);
};

#endif // !defined(AFX_STRINGPARSER_H__43F2DFBF_594B_4503_9192_6FE132805A87__INCLUDED_)

 

实现文件

// StringParser.cpp: implementation of the CStringParser class.
//
//////////////////////////////////////////////////////////////////////

#include "StringParser.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CStringParser::CStringParser()
{

}

CStringParser::~CStringParser()
{

}

/*
* 
 "AV" to "4156"
 */
void CStringParser::ConverToHexString(string& strHexData, const char* pszSrc, int nLen)
{
 for (int i = 0; i < nLen; i++)
 {
  char szBuf[3] = {0};
        sprintf(szBuf, "%02X", (unsigned char)pszSrc[i]);
        strHexData += szBuf;
 }
}

/*
* 
 "4156" to "AV"
 */
int CStringParser::HexStringToString(unsigned char* strDest, int nDestLen, const char* pszHexSrc)
{
 int nRt = 0;
 
 if (NULL == pszHexSrc)
 {
  return 0;
 }

 int nLen = strlen(pszHexSrc);
 if (nLen == 0 || nLen % 2 != 0)
 {
  return 0;
 }
    for (int i = 0; i < nLen; i++)
 {  
  if (nRt > nDestLen)
  {
   return 0;
  }
        strDest[nRt] = CStringParser::GetCharValue(pszHexSrc[i]) * 16;
  strDest[nRt] += CStringParser::GetCharValue(pszHexSrc[++i]);
  nRt++;  
 }
 return nRt;
}

/*
 *  "A" -> 10 "b"-> 11
 */
unsigned char CStringParser::GetCharValue(char cAscii)
{
    unsigned char cRt = 0;
 for (int i = 0 ; i < 22; i++)
 {
  if (c2a[i].c == cAscii)
   return c2a[i].bValue;
 }
 return cRt;
}