.NET Remoting编程四 服务器对象生存期

默认对象的租赁期是5分钟,但我们可以自己配置,也可通过程序设定租赁时间
1.配置实现(它对这个应用程序中的所有对象都适用)

<?xml version="1.0" encoding="utf-8" ?> 
<configuration>
    <system.runtime.remoting>
        <application>
            <lifetime leaseTime="10s" renewOnCallTime="5s"/>
            <!--Config Server and channels as before-->
        </application>
    </system.runtime.remoting>
</configuration>

2.程序实现
程序实现的好处在于可以为每个类型都定义适合自己的租赁租,必须为每个类型写入代码,也可以通过继承于MarshByRefObject类的一个方法InitializeLifetimeServices来设置.运行库会在创建对象时调用这个方法.

 1using System;
 2using System.Runtime.Remoting;
 3using System.Runtime.Remoting.Lifetime;
 4
 5namespace CheckLife
 6{
 7    /**//// <summary>
 8    /// Customer 的摘要说明。
 9    /// </summary>
10    public class Customer:MarshalByRefObject
11    {
12        string mName;
13        public Customer(string name)
14        {
15            Console.WriteLine("Customer.ctor({0})",name);
16            mName = name;
17        }
18        public Customer()
19        {
20            //
21            // TODO: 在此处添加构造函数逻辑
22            //
23        }
24        public override object InitializeLifetimeService()
25        {
26            ILease leaseInfo = (ILease)base.InitializeLifetimeService();
27            leaseInfo.InitialLeaseTime = TimeSpan.FromSeconds(7);
28            leaseInfo.RenewOnCallTime = TimeSpan.FromSeconds(3);
29            return leaseInfo;
30        }
31
32        public string SayHello()
33        {
34            Console.WriteLine("Customemr.SayHello()");
35            Diagnostics.ShowLeaseInfo((ILease)this.GetLifetimeService());
36            return "Hello"+mName;        
37        }        
38    }
39}

通过如下类查看对象租赁期情况:

 1using System;
 2using System.Runtime;
 3using System.Runtime.Remoting;
 4using System.Runtime.Remoting.Lifetime;
 5namespace CheckLife
 6{
 7    /**//// <summary>
 8    /// Diagnostics 的摘要说明。
 9    /// </summary>
10    public class Diagnostics
11    {
12        public static void ShowLeaseInfo(ILease leaseInfo)
13        {
14            Console.WriteLine("Lease Info.");
15            if(leaseInfo != null)
16            {
17                Console.WriteLine("Current Lease time:{0}:{1}",leaseInfo.CurrentLeaseTime.Minutes,leaseInfo.CurrentLeaseTime.Seconds);
18                Console.WriteLine("Initial Lease Time:{0}:{1}",leaseInfo.InitialLeaseTime.Minutes,leaseInfo.InitialLeaseTime.Seconds);
19                Console.WriteLine("Renew on call Time:{0}:{1}",leaseInfo.RenewOnCallTime.Minutes,leaseInfo.RenewOnCallTime.Seconds);
20                Console.WriteLine("Current state:{0}",leaseInfo.CurrentState);
21            }
22            else
23            {
24                Console.WriteLine("No Lease Info!!");
25            }
26        }
27    }
28}

服务器端程序:

 1using System;
 2using System.Runtime;
 3using System.Runtime.Remoting;
 4using System.Runtime.Remoting.Channels;
 5using System.Runtime.Remoting.Channels.Http;
 6
 7namespace CheckLife
 8{
 9    /**//// <summary>
10    /// ServerMain 的摘要说明。
11    /// </summary>
12    public class ServerMain
13    {
14        public ServerMain()
15        {
16            //
17            // TODO: 在此处添加构造函数逻辑
18            //
19        }
20        public static void Main(string[] args)
21        {
22            HttpServerChannel channel = new HttpServerChannel(13101);
23            ChannelServices.RegisterChannel(channel);
24            RemotingConfiguration.RegisterActivatedServiceType(typeof(Customer));
25            Console.WriteLine("Server Started..");
26            Console.ReadLine();
27        }
28    }
29}

客户端程序:

 1using System;
 2using System.Runtime.Remoting;
 3using System.Runtime.Remoting.Channels;
 4using System.Runtime.Remoting.Channels.Http;
 5
 6namespace CheckLife
 7{
 8    /**//// <summary>
 9    /// ClientMain 的摘要说明。
10    /// </summary>
11    public class ClientMain
12    {
13        public ClientMain()
14        {
15            //
16            // TODO: 在此处添加构造函数逻辑
17            //
18        }
19        public static void Main(string[] args)
20        {
21            RemotingConfiguration.RegisterActivatedClientType(typeof(Customer),"http://localhost:13101");
22            Customer cust = new Customer("Homer");
23            Console.WriteLine(cust.SayHello());                
24        }
25    }
26}

后记:
如果想设置无限的租赁,则在InitializeLifetimeService()中返回null对象来实现:

1public override object InitializeLifetimeService()
2{
3       return null;
4}