System.Configuration.XmlUtilWriter.AppendEscapeXmlString C# (CSharp) Метод

        internal int AppendEscapeXmlString(string s, bool inAttribute, char quoteChar) {
            int charactersWritten = 0;
            for (int i = 0; i < s.Length; i++) {
                char ch = s[i];

                bool appendCharEntity = false;
                string entityRef = null;
                if ((ch < 32 && ch != '\t' && ch != '\r' && ch != '\n') || (ch > 0xFFFD)) {
                    appendCharEntity = true;
                }
                else {
                    switch (ch)
                    {
                        case '<':
                            entityRef = "lt";
                            break;

                        case '>':
                            entityRef = "gt";
                            break;

                        case '&':
                            entityRef = "amp";
                            break;

                        case '\'':
                            if (inAttribute && quoteChar == ch) {
                                entityRef = "apos";
                            }
                            break;

                        case '"':
                            if (inAttribute && quoteChar == ch) {
                                entityRef = "quot";
                            }
                            break;

                        case '\n':
                        case '\r':
                            appendCharEntity = inAttribute;
                            break;

                        default:
                            break;
                    }
                }

                if (appendCharEntity) {
                    charactersWritten += AppendCharEntity(ch);
                }
                else if (entityRef != null) {
                    charactersWritten += AppendEntityRef(entityRef);
                }
                else {
                    charactersWritten += Write(ch);
                }
            }

            return charactersWritten;
        }