c++两个常用函数:1.二进制字符串2 hex（十六进制）。2. 栈变量字符串2堆变量

二进制字符串2 hex

string get_b2hex(const char * source,int len)
{
std::string strHexPack;
for (int i = 0; i < len; ++i)
{
unsigned char c = source[i];
unsigned int nIntVal = c;
char hex_buf[10] = {0};
sprintf(hex_buf, "%02x", nIntVal);
strHexPack += hex_buf;
}
return strHexPack;
//printf("*********strHexPack:%s/n", strHexPack.c_str());
}

栈变量字符串2堆变量

const char* CopyStr(const std::string& strResult)
{
//const char* '/0'
const char * t_t_tempchar = (const char *)strResult.data();

char * charResult = (char*)malloc(sizeof(char) * strResult.size() + 1);

charResult[strResult.size()] = '/0';

strcpy(charResult, t_t_tempchar);

return charResult;

}