[ServiceContract]
    public interface IDomain
    {
        [OperationContract]
        [WebGet(UriTemplate = "ClientAccessPolicy.xml")]
        Message ProvidePolicyFile();
    }

  [ServiceContract]
    public interface ISiteService
    {
        [OperationContract]
        List<Site> GetSites();
    }

  [DataContract]
    public class Site
    {
        [DataMember]
        public string GID { get; set; }
 
        [DataMember]
        public string SiteName { get; set; }
 
        [DataMember]
        public string Geom { get; set; }
    }

  public class DomainService : IDomain
    {
        public System.ServiceModel.Channels.Message ProvidePolicyFile()
        {
            MemoryStream ms = new MemoryStream();
            using (FileStream fs = File.OpenRead(@"clientaccesspolicy.xml"))
            {
                int length = (int)fs.Length;
                byte[] data = new byte[length];
                fs.Position = 0;
                fs.Read(data, 0, length);
                ms = new MemoryStream(data);
            }
            XmlReader reader = XmlReader.Create(ms);
            Message result = Message.CreateMessage(MessageVersion.None, "", reader);
            return result;
        }
    }

 public class SiteService:ISiteService
    {
        private DataSet ds = new DataSet();
        private DataTable dt = new DataTable();
        public List<Site> GetSites()
        {
            List<Site> source = new List<Site>();
            try
            {
                // PostgeSQL-style connection string        
                string connstring = String.Format("Server={0};Port={1};User Id={2};Password={3};Database={4};", "localhost", "5432", "postgres", "sa", "postgis20");
                // Making connection with Npgsql provider           
                NpgsqlConnection conn = new NpgsqlConnection(connstring);
                conn.Open();
                // quite complex sql statement                  
                // data adapter making request from our connection
                //string sql = "SELECT * from cellcover_region";
                string sql = "SELECT a.* FROM public.cellcover_region as a, site_font_point as b where b.gid=1 and ST_Within(b.geom,a.geom)";
                NpgsqlDataAdapter da = new NpgsqlDataAdapter(sql, conn);          
                ds.Reset();
                // filling DataSet with result from NpgsqlDataAdapter        
                da.Fill(ds);
                // since it C# DataSet can handle multiple tables, we will select first           
                dt = ds.Tables[0]; 
                int count = dt.Rows.Count;
                for (int i = 0; i < count; i++)
                {
                    DataRow dr = dt.Rows[i];
                    Site site = new Site
                    {
                        GID = dr[0].ToString(),
                        SiteName = dr[1].ToString(),
                        Geom = dr[2].ToString()
                    };
                    source.Add(site);
                }
                conn.Close();
            }
            catch (Exception ex)
            {
                throw ex;
            }
            return source;
        }
    }

  static void Main(string[] args)
        {
            ServiceHost host = new ServiceHost(typeof(SiteService));
            ServiceHost crossDomainserviceHost = new ServiceHost(typeof(DomainService));
            host.Opened += delegate
            {
                Console.WriteLine("服務(wù)已經(jīng)啟動(dòng)，按任意鍵終止...");
            };
 
            crossDomainserviceHost.Opened += delegate
            {
                Console.WriteLine("跨域服務(wù)已經(jīng)啟動(dòng)，按任意鍵終止...");
            };
            crossDomainserviceHost.Open();
            host.Open();
            Console.ReadKey();
            host.Close();
            host.Abort();
            crossDomainserviceHost.Close();
            crossDomainserviceHost.Abort();
        }