当 字符串 中有’\0’时无法通过 tcp 将内容发送的客户端，因此需要将原始字符串转换为16 进制 表示的形式然后进行发送，发送后要对16进制的字符串进行转换，以下代码就是解决16进制转 string 的。

# include <iostream>

#include <string>

#include <malloc.h>

#include <cstring>

#include <cstdlib>

#include <cstdio>

using namespace std;

char * HexToStr(char *pbSrc, int nLen)

{

char ddl, ddh;

char *pbDest;

pbDest = (char *)malloc(nLen/2+1);

memset (pbDest,0,nLen/2);

int i;

for (i = 0; i <= nLen-2; i+=2)

{

if(pbSrc[i] >= 48 && pbSrc[i] <= 57)

{

ddh = (pbSrc[i]-48)*16;

}

if(pbSrc[i] >= 65 && pbSrc[i] <= 70)

{

ddh = (pbSrc[i] – 55)*16;

}

if(pbSrc[i] >= 97 && pbSrc[i] <= 102)

{

ddh = (pbSrc[i] – 87)*16;

}

if(pbSrc[i+1] >= 48 && pbSrc[i+1] <= 57)

{

ddl = pbSrc[i+1]-48;

}

if(pbSrc[i+1] >= 65 && pbSrc[i+1] <= 70)

{

ddl = pbSrc[i+1] – 55;

}

if(pbSrc[i+1] >= 97 && pbSrc[i+1] <= 102)

{

ddl = pbSrc[i+1] – 87;

}

pbDest[i/2] = ddh+ddl;

}

pbDest[nLen/2+1] = ‘\0’;

return pbDest;

}

int main()

{

char *test = (char *)”68656c6c6f20776f726c64″;

char *ptr=nullptr;

ptr = HexToStr(test, 22);

cout << ptr << endl;

free(ptr);

return 0;

}