一步一步学Linq to sql（十）：分层构架的例子

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.ServiceModel;

namespace Contract

{

    [ServiceContract]

    public interface IDataAccess

    {

        [OperationContract]

        void SendMessage(TbGuestBook gb);

        [OperationContract]

        List<TbGuestBook> GetData();

        [OperationContract]

        void DeleteMessage(string ID);

        [OperationContract]

        void SendReply(TbGuestBook gb);

    }

}

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using Contract;

using System.Data.Linq.Mapping;

using System.IO;

using System.ServiceModel;

namespace Service

{

    [ServiceBehavior(IncludeExceptionDetailInFaults = true)]

    public class DataAccess : IDataAccess

    {

        GuestBook ctx;

        public DataAccess()

        {

            XmlMappingSource xms = XmlMappingSource.FromXml(File.ReadAllText("c:\\guestbook.map"));

            ctx = new GuestBook("server=srv-devdbhost;database=GuestBook;uid=sa;pwd=Abcd1234", xms);

            ctx.Log = Console.Out;

        }

        public void SendMessage(TbGuestBook gb)

        {

            ctx.TbGuestBook.Add(gb);

            ctx.SubmitChanges();

        }

        public List<TbGuestBook> GetData()

        {

            var query = from gb in ctx.TbGuestBook orderby gb.PostTime descending select gb;

            return query.ToList();

        }

        public void DeleteMessage(string ID)

        {

            TbGuestBook gb = ctx.TbGuestBook.Single(message => message.ID == new Guid(ID));

            ctx.TbGuestBook.Remove(gb);

            ctx.SubmitChanges();

        }

        public void SendReply(TbGuestBook gb)

        {

           //ctx.ExecuteCommand("update tbGuestBook set reply={0},isreplied=1 where ID={1}", gb.Reply, gb.ID);

            TbGuestBook record = ctx.TbGuestBook.Single(message => message.ID == gb.ID);

            record.IsReplied = true;

            record.Reply = gb.Reply;

            ctx.SubmitChanges();

        }

    }

}