WCF体验之旅（8）：WCF中的Session和Instancing Management

来源：博客园作者：Artech 出处：巧巧读书 2008-03-18 进入讨论组

我们先采用默认的Session和Instance Context Modle，在这之前我们看看整个Solution各个部分的定义：

1、Service Contract：ICalculator

using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
namespace Artech.SessionfulCalculator.Contract
{
[ServiceContract]
public interface ICalculator
{
[OperationContract(IsOneWay = true)]
void  Adds(double x);
[OperationContract]
double GetResult();
}
}

2、Service Implementation：CalculatorService

using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
using Artech.SessionfulCalculator.Contract;
namespace Artech.SessionfulCalculator.Service
{
public class CalculatorService:ICalculator
{
private double _result;
ICalculator Members#region ICalculator Members
public void Adds(double x)
{
Console.WriteLine("The Add method is invoked and the current session ID is: {0}",
OperationContext.Current.SessionId);
this._result += x;
}
public double GetResult()
{
Console.WriteLine("The GetResult method is invoked and the current session ID is: 
{0}", OperationContext.Current.SessionId);
return this._result;
}
#endregion
public CalculatorService()
{
Console.WriteLine("Calculator object has been created");
}
~CalculatorService()
{
Console.WriteLine("Calculator object has been destoried");
}
}
}

为了让大家对Service Instance的创建和回收有一个很直观的认识，我特意在Contructor和Finalizer中作了一些指示性的输出。同时在每个Operation中输出的当前的Session ID

3、Hosting

Program

using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
using Artech.SessionfulCalculator.Service;
using System.Threading;
namespace Artech.SessionfulCalculator.Hosting
{
class Program
{
static void Main(string[] args)
{
using(ServiceHost host = new ServiceHost(typeof(CalculatorService)))
{
host.Opened += delegate
{
Console.WriteLine("The Calculator service has begun to listen");
};
host.Open();
Timer timer = new Timer(delegate { GC.Collect(); }, null, 0, 100);
Console.Read();
}
}
}
}