XML新增、修改、选择

using System;
using System.Linq;
using System.Xml.Linq;
using DFS.Kiosk.Provider.Simulator.Common.Utilities;
using DFS.Kiosk.Provider.Simulators.Utilities;

namespace DFS.Kiosk.Provider.Simulator.Common.Data
{
    public static class DataAccessor
    {
        private static readonly object ReadWriteLock = new object();

        private static XDocument _doc;

        private const string XmlFileName = "Data/ValidTickets.xml";

        private static XDocument Doc
        {
            get { return _doc ?? (_doc = XDocument.Load(XmlFileName)); }
        }

        public static string ReadTicket(string ticketNumber, TicketStatus ticketstatus)
        {
            try
            {
                lock (ReadWriteLock)
                {
                    XElement element = (from elem in Doc.Elements().Descendants()
                        where elem.Value == ticketNumber && elem.Attribute("status").Value == ticketstatus.ToString()
                        select elem).FirstOrDefault();
                    return element != null ? element.Attribute("amount").Value : "";
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLogger(ex, ConstValues.MainLogFileName);
            }
            return "";
        }

        public static string ReadKonamiTicket(string ticketNumber, TicketStatus ticketstatus)
        {
            try
            {
                lock (ReadWriteLock)
                {
                    XElement element = (from elem in Doc.Elements().Descendants()
                                        where elem.Value.Substring(,) == ticketNumber && elem.Attribute("status").Value == ticketstatus.ToString()
                                        select elem).FirstOrDefault();
                    return element != null ? element.Attribute("amount").Value : "";
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLogger(ex, ConstValues.MainLogFileName);
            }
            return "";
        }

        public static string ReadTicket(string ticketNumber, string attribute)
        {
            try
            {
                lock (ReadWriteLock)
                {
                    XElement element =
                        (from elem in Doc.Elements().Descendants() where elem.Value == ticketNumber select elem)
                            .FirstOrDefault();
                    if (attribute == "status")
                    {
                        return element != null ? element.Attribute("status").Value : TicketStatus.NotFound.ToString();
                    }
                    if (attribute == "amount")
                    {
                        return element != null ? element.Attribute("amount").Value : "";
                    }
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLogger(ex, ConstValues.MainLogFileName);
            }
            return "";
        }

        public static bool WriteTicket(string ticketNumber, TicketStatus oldStatus, TicketStatus newStatus)
        {
            try
            {
                lock (ReadWriteLock)
                {
                    XElement element = (from elem in Doc.Elements().Descendants()
                        where elem.Value == ticketNumber && elem.Attribute("status").Value == oldStatus.ToString()
                        select elem).FirstOrDefault();
                    if (element != null)
                    {
                        element.Attribute("status").Value = newStatus.ToString();
                        return true;
                    }
                    return false;
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLogger(ex, ConstValues.MainLogFileName);
                return false;
            }
        }

        public static bool WriteKonamiTicket(string ticketNumber, TicketStatus oldStatus, TicketStatus newStatus)
        {
            try
            {
                lock (ReadWriteLock)
                {
                    XElement element = (from elem in Doc.Elements().Descendants()
                                        where elem.Value.Substring(,) == ticketNumber && elem.Attribute("status").Value == oldStatus.ToString()
                                        select elem).FirstOrDefault();
                    if (element != null)
                    {
                        element.Attribute("status").Value = newStatus.ToString();
                        return true;
                    }
                    return false;
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLogger(ex, ConstValues.MainLogFileName);
                return false;
            }
        }

        /// <summary>
        ///     Creates ticket, add xml node into ValidTickets.xml file
        /// </summary>
        /// <param name="amount">The amount.</param>
        /// <returns></returns>
        public static string CreateTicket(string amount)
        {
            try
            {
                lock (ReadWriteLock)
                {
                    XElement lastTiket = Doc.Elements().Descendants().Last();
                    string number = (long.Parse(lastTiket.Value) + ).ToString();

                    //if number.lenght<18 fill with "0" at start
                    while (number.Length < )
                    {
                        number = "" + number;
                    }
                    //get 18 character in case number.lengh>18
                    string ticketNumber = number.Substring(number.Length - , );

                    //add new ticket to xdocoment
                    var newNode = new XElement("ValidVoucher",
                        new XAttribute("status", TicketStatus.pending),
                        new XAttribute("amount", amount));
                    newNode.SetValue(ticketNumber);
                    if (Doc.Root != null) Doc.Root.Add(newNode);

                    return ticketNumber;
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLogger(ex, ConstValues.MainLogFileName);
                return "";
            }
        }

        public static bool Reset()
        {
            try
            {
                lock (ReadWriteLock)
                {
                    _doc = XDocument.Load(XmlFileName);
                }
            }
            catch (Exception ex)
            {
                Logger.WriteLogger(ex, ConstValues.MainLogFileName);
                return false;
            }
            return true;
        }
    }
}