利用WCF的callback机制开发一个简单的多人游戏模型

本文介绍了如何利用WCF和callback机制开发一个简单的多人在线游戏模型。

运行过程如下：

当game service 启动之后，若干个客户端便会自动连接到服务器。当某个客户端点击join game时，所有客户端同时更新。

运行screenshot如下图所示：

WCF service screenshot

client1 screenshot:

client2 screenshot:

WCF service主要代码如下：

using  System;
using  System.Collections.Generic;
using  System.Linq;
using  System.Text;
using  System.ServiceModel;

namespace  GameService
{
     public   class  PlayerEventAgrs : EventArgs
    {
        public  Player player;
        public  GameDesk desk;
    }


    [ServiceBehavior(InstanceContextMode = InstanceContextMode.PerSession)]
     class  GameService:IGameService
    {
         static  List < Player >  Players = new  List < Player > ();
         public   delegate   void  PlayerEventHandler( object  sender, PlayerEventAgrs e);
         public   static   event  PlayerEventHandler OnJoinGame;
         public   static   event  PlayerEventHandler OnStartGame;

         public  IPlayerCallBack callback;
       
         public  GameService()
        {
            callback  =  System.ServiceModel.OperationContext.Current.GetCallbackChannel < IPlayerCallBack > ();
            OnJoinGame  +=   new  PlayerEventHandler(GameService_OnJoinGame);
            OnStartGame  +=   new  PlayerEventHandler(GameService_OnStartGame);
              
        }


         public  List < Player >  GetPlayerList()
        {
            System.Threading.Thread.Sleep( 4000 );
             return  Players;
        }

         void  GameService_OnJoinGame( object  sender, PlayerEventAgrs e)
        {
            Console.WriteLine( " {0} is joining the game on desk NO {1} " , e.player.PlayerName, e.desk.DeskNo);
            callback.OnJoin(e.player,e.desk);
        }

         void  GameService_OnStartGame( object  sender, PlayerEventAgrs e)
        {
            callback.OnStart(e.player);
        }
      
         public   void  BroadGameEvent(PlayerEventAgrs e, PlayerEventHandler temp)
        {
             if  (OnJoinGame  !=   null )
            {
                 foreach  (PlayerEventHandler handler  in  temp.GetInvocationList())
                {
                    handler.BeginInvoke( this , e,  null ,  null );
                }
            }
        }

              
         public   void  JoinToGame(Player player,GameDesk desk)
        {
            Players.Add(player);    

            PlayerEventAgrs e  =   new  PlayerEventAgrs();
            e.player  =  player;
            e.player.PositionNO  =  desk;
            e.desk  =  desk;
            BroadGameEvent(e, OnJoinGame);
        }

         public   void  StartGame(Player player)
        {
            PlayerEventAgrs e  =   new  PlayerEventAgrs();
            e.player  =  player;
            BroadGameEvent(e, OnStartGame);
        }
      
    }
}

callback interface如下：

using  System;
using  System.Collections.Generic;
using  System.Linq;
using  System.Text;
using  System.ServiceModel;
using  System.Runtime.Serialization;

namespace  GameService
{
    [ServiceContract]
     public   interface  IPlayerCallBack
    {
        [OperationContract(IsOneWay  =   true )]
         void  OnJoin(Player player,GameDesk gamedesk);
    
        [OperationContract(IsOneWay  =   true )]
         void  OnStart(Player player);
    }
}

客户端callback implementation如下：

  #region  CallBack Implementation
         public   void  OnJoin(GameService.Player player, GameService.GameDesk desk)
        {           
             int  deskNo  =  desk.DeskNo;
            StringBuilder show  =   new  StringBuilder();;
            show.AppendFormat( " Player Information\n " );
            show.AppendFormat( " Player Name:{0}\n " , player.PlayerName);
            show.AppendFormat( " Player Status: {0}\n " ,player.Action);
            show.AppendFormat( " Player Role: {0}\n " , player.Role);

            img_Desktop.Image  =   new  System.Drawing.Bitmap(System.Drawing.Image.FromFile( @" image\active-desktop.bmp " ));                   
             switch  (deskNo)
            {
                 case   1 :                   
                    lb_PlayerInfo1.Text  =  show.ToString();
                    lb_PlayerInfo1.Refresh();
                    pic_Player1.Image = new  System.Drawing.Bitmap(System.Drawing.Image.FromFile( @" image\acvite-icon.bmp " ));                   
                     break ;
                 case   2 :
                    lb_PlayerInfo2.Text  =  show.ToString();                  
                    pic_Player2.Image  =   new  System.Drawing.Bitmap(System.Drawing.Image.FromFile( @" image\acvite-icon.bmp " ));
                     break ;
                 case   3 :
                    lb_PlayerInfo3.Text  =  show.ToString();                   
                    pic_Player3.Image  =   new  System.Drawing.Bitmap(System.Drawing.Image.FromFile( @" image\acvite-icon.bmp " ));
                     break ;
                
            }     
    
        }

         public   void  OnStart(GameService.Player player)
        {

        }
         #endregion

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