C++ HTTP 请求 URL编码

std::string UrlEncode(const std::string& szToEncode){std::string src = szToEncode;char hex[] = "0123456789ABCDEF";string dst;for (size_t i = 0; i < src.size(); ++i){unsigned char cc = src[i];if (isascii(cc)){if (cc == ' '){dst += "%20";}else if(cc =='\r'){dst+="%0D";}else if(cc =='\n'){dst+="%0A";}elsedst += cc;}else{unsigned char c = static_cast<unsigned char>(src[i]);dst += '%';dst += hex[c / 16];dst += hex[c % 16];}}return dst;}