ws2s函数

std::string ws2s(const std::wstring& str)
{
    char*     pElementText;
    int    iTextLen;
    // wide char to multi char
    iTextLen = WideCharToMultiByte(CP_ACP, 0, str.c_str(), -1, NULL, 0, NULL, NULL);
    pElementText = new char[iTextLen + 1];
    memset((void*)pElementText, 0, sizeof(char)* (iTextLen + 1));
    ::WideCharToMultiByte(CP_ACP, 0, str.c_str(), -1, pElementText, iTextLen, NULL, NULL);
    std::string strText;
    strText = pElementText;
    delete[] pElementText;
    return strText;
}

std::string strKEy = ws2s(pKey);//pKey为WCHAR类型
    char pStr[256] = {0};
    strcpy_s(pStr, 256, strKEy.c_str());