c++截取##内字符

/***********************************************************************
Functions:  Trim(string& sStr)
Purpose:  截去字符串两端的空格或TAB
Parameter:  sStr------------字符串
Return:   无
Usage:    #str="   China   ";
Trim(str);
#str="China";
************************************************************************/
void  CMacSnStr::Trim(string& sStr)
{
  if (sStr.length() == 0){
    return;
  }
  string::iterator pos = sStr.end() - 1;
  for (; pos >= sStr.begin();){
    if (*pos == ' ' ||
      *pos == '\t' ||
      *pos == '\n' ||
      *pos == '\r'){
      sStr.erase(pos);
      pos = sStr.end() - 1;
    }
    else
      break;
  }

  pos = sStr.begin();
  for (; pos<sStr.end();){
    if (*pos == ' ' ||
      *pos == '\t' ||
      *pos == '\n' ||
      *pos == '\r'){
      sStr.erase(pos);
      pos = sStr.begin();
    }
    else
      break;
  }
}

int CMacSnStr::FindGV(const string strorig, string& strgv)
{
  char* cpBeginPos = NULL;
  char* cpEndPos = NULL;
  cpBeginPos = (char*)strchr(strorig.c_str(), '#');
  if (cpBeginPos != NULL)
    cpEndPos = strchr(cpBeginPos + 1, '#');

  if (cpBeginPos != NULL && cpEndPos != NULL){
    strgv = strorig.substr(cpBeginPos - strorig.c_str(), cpEndPos - cpBeginPos + 1);
    return 0;
  }
  else{
    return -1;
  }
}