System.Xml.XmlConvert.ToXPathString C# (CSharp) Method

        internal static String ToXPathString(Object value)
        {
            string s = value as string;
            if (s != null)
            {
                return s;
            }
            else if (value is double)
            {
                return ((double)value).ToString("R", NumberFormatInfo.InvariantInfo);
            }
            else if (value is bool)
            {
                return (bool)value ? "true" : "false";
            }
            else
            {
                return Convert.ToString(value, NumberFormatInfo.InvariantInfo);
            }
        }