System.Xml.DtdParser.ParseExternalId C# (CSharp) Méthode

        private void ParseExternalId(Token idTokenType, Token declType, out string publicId, out string systemId)
        {
            LineInfo keywordLineInfo = new LineInfo(LineNo, LinePos - 6);
            publicId = null;
            systemId = null;

            if (GetToken(true) != Token.Literal)
            {
                ThrowUnexpectedToken(_curPos, "\"", "'");
            }

            if (idTokenType == Token.SYSTEM)
            {
                systemId = GetValue();

                if (systemId.IndexOf('#') >= 0)
                {
                    Throw(_curPos - systemId.Length - 1, SR.Xml_FragmentId, new string[] { systemId.Substring(systemId.IndexOf('#')), systemId });
                }

                if (declType == Token.DOCTYPE && !_freeFloatingDtd)
                {
                    _literalLineInfo.linePos++;
                    _readerAdapter.OnSystemId(systemId, keywordLineInfo, _literalLineInfo);
                }
            }
            else
            {
                Debug.Assert(idTokenType == Token.PUBLIC);
                publicId = GetValue();

                // verify if it contains chars valid for public ids
                int i;
                if ((i = _xmlCharType.IsPublicId(publicId)) >= 0)
                {
                    ThrowInvalidChar(_curPos - 1 - publicId.Length + i, publicId, i);
                }

                if (declType == Token.DOCTYPE && !_freeFloatingDtd)
                {
                    _literalLineInfo.linePos++;
                    _readerAdapter.OnPublicId(publicId, keywordLineInfo, _literalLineInfo);

                    if (GetToken(false) == Token.Literal)
                    {
                        if (!_whitespaceSeen)
                        {
                            Throw(SR.Xml_ExpectingWhiteSpace, new string(_literalQuoteChar, 1), (int)_literalLineInfo.lineNo, (int)_literalLineInfo.linePos);
                        }
                        systemId = GetValue();
                        _literalLineInfo.linePos++;
                        _readerAdapter.OnSystemId(systemId, keywordLineInfo, _literalLineInfo);
                    }
                    else
                    {
                        ThrowUnexpectedToken(_curPos, "\"", "'");
                    }
                }
                else
                {
                    if (GetToken(false) == Token.Literal)
                    {
                        if (!_whitespaceSeen)
                        {
                            Throw(SR.Xml_ExpectingWhiteSpace, new string(_literalQuoteChar, 1), (int)_literalLineInfo.lineNo, (int)_literalLineInfo.linePos);
                        }
                        systemId = GetValue();
                    }
                    else if (declType != Token.NOTATION)
                    {
                        ThrowUnexpectedToken(_curPos, "\"", "'");
                    }
                }
            }
        }
        //