使用用WCF中的双工（Duplex）模式将广告图片推送到每个Winform客户端机子上

参考资料地址：http://www.cnblogs.com/server126/archive/2011/08/11/2134942.html

代码实现：

　　WCF宿主（服务端）

IServices.cs 服务契约（其实就是接口）

namespace Host
{
    [ServiceContract(SessionMode = SessionMode.Required, CallbackContract = typeof(ICallBackServices))]
    public interface IServices
    {
       /// <summary>
       /// 注册客户端信息
       /// </summary>
        [OperationContract(IsOneWay = false)]
        void Register();
    }
    /// <summary>
    ///  回调接口
    /// </summary>
    public interface ICallBackServices
    {
        /// <summary>
        /// 服务像客户端发送信息(异步)
        /// </summary>
        /// <param name="Message"></param>
        [OperationContract(IsOneWay = true)]
        void SendMessage(string Message);

        /// <summary>
        /// 服务端像客户端(异步)发送图片流
        /// </summary>
        /// <param name="messageEntity"></param>
        [OperationContract(IsOneWay = true)]
        void SendPicStream(MessageEntity messageEntity);
    }
} 

MessageEntity.cs 消息实体类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Runtime.Serialization;

namespace WcfDuplex
{
    /// <summary>
    /// 消息实体类
    /// </summary>
    [DataContract]
    public class MessageEntity
    {
        [DataMember]
        public string Content { get; set; }

        [DataMember]
        public byte[] PicStream { get; set; }
    }
}

Services.cs

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

namespace Host
{
    /// <summary>
    ///  实例使用Single，共享一个
    ///  并发使用Mutiple, 支持多线程访问(一定要加锁)
    /// </summary>
    [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single, ConcurrencyMode = ConcurrencyMode.Multiple)]
    public class Services : IServices
    {
        public static readonly string SendMessageType = ConfigurationManager.ConnectionStrings["SendMessageType"].ToString();
        private static readonly object InstObj = new object();//单一实例
        //public static List<ICallBackServices> RegList = null;
        public static Dictionary<string, ICallBackServices> DicHost = null; //记录机器名称
        public static Dictionary<string, ICallBackServices> DicHostSess = null;//记录Sessionid
        public Services()
        {
            //RegList = new List<ICallBackServices>();
            DicHost = new Dictionary<string, ICallBackServices>();
            DicHostSess = new Dictionary<string, ICallBackServices>();
        }
        #region IServices 成员

        public void Register()
        {
            ICallBackServices client = OperationContext.Current.GetCallbackChannel<ICallBackServices>();
            string sessionid = OperationContext.Current.SessionId;//获取当前机器Sessionid--------------------------如果多个客户端在同一台机器，就使用此信息。
            string ClientHostName = OperationContext.Current.Channel.RemoteAddress.Uri.Host;//获取当前机器名称-----多个客户端不在同一台机器上，就使用此信息。
            OperationContext.Current.Channel.Closing += new EventHandler(Channel_Closing);//注册客户端关闭触发事件
            if (SendMessageType.ToUpper() == "SESSIONID")
            {
                DicHostSess.Add(sessionid, client);//添加
            }
            else
            {
                DicHost.Add(ClientHostName, client); //添加
            }
            //RegList.Add(client);//添加
        }
        void Channel_Closing(object sender, EventArgs e)
        {
            lock (InstObj)//加锁，处理并发
            {
                //if (RegList != null && RegList.Count > 0)
                //    RegList.Remove((ICallBackServices)sender); 
                if (SendMessageType.ToUpper() == "SESSIONID")
                {
                    if (DicHostSess != null && DicHostSess.Count > 0)
                    {
                        foreach (var d in DicHostSess)
                        {
                            if (d.Value == (ICallBackServices)sender)//删除此关闭的客户端信息
                            {
                                DicHostSess.Remove(d.Key);
                                break;
                            }
                        }
                    }
                }
                else
                {
                    if (DicHost != null && DicHost.Count > 0) //同上
                    {
                        foreach (var d in DicHost)
                        {
                            if (d.Value == (ICallBackServices)sender)
                            {
                                DicHost.Remove(d.Key);
                                break;
                            }
                        }
                    }
                }
            }
        }
        #endregion
    }
} 

服务端

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.ServiceModel;
using System.Threading;
using WcfDuplex;
using System.IO;

namespace Host
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private static readonly object InstObj = new object();
        private static bool isval = true;
        private void Form1_Load(object sender, EventArgs e)
        {
            ServiceHost host = new ServiceHost(typeof(Services));
            host.Open();
            this.Text = "wcf服务启动成功！";

            #region 初始化ListBox
            Thread thread = new Thread(new ThreadStart(delegate   ///监听所有客户端连接，并添加到ListBox控件里
            {
                lock (InstObj)//加锁
                {
                    while (true)
                    {

                        if (Services.SendMessageType.ToUpper() == "SESSIONID")
                        {
                            if (Services.DicHostSess != null || Services.DicHostSess.Count > 0)
                            {
                                this.Invoke(new MethodInvoker(delegate { this.listBox1.Items.Clear(); }));
                                foreach (var l in Services.DicHostSess)
                                {
                                    this.Invoke(new MethodInvoker(delegate
                                    {
                                        this.listBox1.Items.Add(l.Key);
                                    }));
                                }
                            }
                        }
                        else
                        {
                            if (Services.DicHost != null || Services.DicHost.Count > 0)
                            {
                                this.Invoke(new MethodInvoker(delegate { this.listBox1.Items.Clear(); }));
                                foreach (var l in Services.DicHost)
                                {
                                    this.Invoke(new MethodInvoker(delegate
                                    {
                                        this.listBox1.Items.Add(l.Key);
                                    }));
                                }
                            }
                        }
                        Thread.Sleep(1000 * 10);
                    }
                }
            }));
            thread.IsBackground = true;
            thread.Start();
            #endregion
        }

        #region 推送
        int i = 0;
        private void button1_Click(object sender, EventArgs e)
        {
            i++;
            if (Services.DicHostSess == null || Services.DicHostSess.Count > 0)
            {
                if (this.listBox1.SelectedItem != null)
                {
                    if (this.listBox1.SelectedItem.ToString() != "")
                    {
                        foreach (var d in Services.DicHostSess)
                        {
                            if (d.Key == this.listBox1.SelectedItem.ToString())
                            {
                                //d.Value.SendMessage(string.Format("Time: {0} message {1}", DateTime.Now, textBox1.Text.Trim()));
                                MessageEntity messageEntity = new MessageEntity();
                                if (i<4)
                                {
                                    string picPath = @"D:downloadwcf推送与广播HostImg" + i + ".jpg";
                                    messageEntity.PicStream = ImageDatabytes(picPath);
                                    d.Value.SendPicStream(messageEntity);
                                }
                            }
                        }
                    }
                }
                else 
                { 
                    MessageBox.Show("请选择要推送给哪台客户端");
                    i--;
                    return; 
                }
            }
            if (Services.DicHost != null || Services.DicHost.Count > 0)
            {
                if (this.listBox1.SelectedItem != null)
                {
                    if (this.listBox1.SelectedItem.ToString() != "")
                    {
                        foreach (var d in Services.DicHost)
                        {
                            if (d.Key == this.listBox1.SelectedItem.ToString())
                            {
                                //d.Value.SendMessage(string.Format("Time: {0} message {1}", DateTime.Now, textBox1.Text.Trim()));
                                MessageEntity messageEntity = new MessageEntity();
                                if (i < 4)
                                {
                                    string picPath = @"D:downloadwcf推送与广播HostImg" + i + ".jpg";
                                    messageEntity.PicStream = ImageDatabytes(picPath);
                                    d.Value.SendPicStream(messageEntity);
                                }
                            }
                        }
                    }
                }
                else 
                { 
                    MessageBox.Show("请选择要推送给哪台客户端");
                    i--;
                    return; 
                }
            }
        } 
        #endregion
        
        #region 广播方式
        private void button2_Click(object sender, EventArgs e)
        {
            if (Services.SendMessageType.ToUpper() == "SESSIONID")//类型
            {
                foreach (var d in Services.DicHostSess)
                {
                    d.Value.SendMessage(this.textBox1.Text);
                }
            }
            else
            {
                foreach (var d in Services.DicHost)
                {
                    d.Value.SendMessage(this.textBox1.Text);
                }
            }
        } 
        #endregion

        #region 根据图片路径将图片转换为二进制流
        /// <summary>
        /// 根据图片路径将图片转换为二进制流
        /// </summary>
        /// <param name="FilePath"></param>
        /// <returns></returns>
        public static byte[] ImageDatabytes(string FilePath)
        {
            if (!File.Exists(FilePath))
                return null;
            Bitmap myBitmap = new Bitmap(Image.FromFile(FilePath));

            using (MemoryStream curImageStream = new MemoryStream())
            {
                myBitmap.Save(curImageStream, System.Drawing.Imaging.ImageFormat.Png);
                curImageStream.Flush();

                byte[] bmpBytes = curImageStream.ToArray();
                //如果转字符串的话
                //string BmpStr = Convert.ToBase64String(bmpBytes);
                return bmpBytes;
            }
        } 
        #endregion

    }
}

WinFormClient.cs 客户端

客户端Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.ServiceModel;

namespace WinFormClient
{
    

    public partial class FormClient : Form
    {
        public FormClient()
        {
            InitializeComponent();
            this.Text = "当前客户端编号为："+DateTime.Now.ToString("yyyyMMddHHmmss");
            try
            {
                Console.WriteLine("create object...");
                CallBack back = new CallBack();
                InstanceContext context = new InstanceContext(back);
                ServiceReference1.ServicesClient client = new ServiceReference1.ServicesClient(context);
                Console.WriteLine("regist.....");
                back.showPic += new CallBack.ShowPic(ShowPicMethod);
                client.Register();
                Console.WriteLine("aucceeded");
                //this.ReceivePic.Image = back.Pic;
            }
            catch (Exception ex) { Console.WriteLine(ex.Message); }
        }

        public void ShowPicMethod(Bitmap bitmap)
        {
            this.ReceivePic.Image = bitmap;
        }
    }

    public class CallBack : ServiceReference1.IServicesCallback
    {
        public delegate void ShowPic(Bitmap bitmap);
        public event ShowPic showPic;

        #region IServicesCallback 成员
        public void SendMessage(string Message)
        {
            Console.WriteLine("[ClientTime{0:HHmmss}]Service Broadcast:{1}", DateTime.Now, Message);
        }

        public void SendPicStream(ServiceReference1.MessageEntity messageEntity)
        {
            this.showPic(GetImage(messageEntity.PicStream));
        }
        #endregion

        #region 将图片二进制流转换为图片
        public static Bitmap GetImage(byte[] ImageDatas)
        {
            try
            {
                //如果是字符串的话
                //byte[] resultBytes = Convert.FromBase64String(ImageDatas);
                using (MemoryStream ImageMS = new MemoryStream())
                {
                    ImageMS.Write(ImageDatas, 0, ImageDatas.Length);
                    Bitmap resultBitmap = new Bitmap(ImageMS);
                    return resultBitmap;
                }
            }
            catch
            {
                return null;
            }
        }
        #endregion
    }
}

 Demo下载地址：http://files.cnblogs.com/files/wgx0428/wcf%E6%8E%A8%E9%80%81%E4%B8%8E%E5%B9%BF%E6%92%AD.zip