之前因?yàn)轫?xiàng)目的關(guān)系，涉及到與服務(wù)器實(shí)時(shí)通信，比如通過GPRS將GPS的位置信息等信息發(fā)送到服務(wù)器，然后再轉(zhuǎn)發(fā)給Silverlight應(yīng)用程序，最后在地圖上標(biāo)示出實(shí)時(shí)的地理位置，查了查相關(guān)的資料，網(wǎng)上給出的比較好的方法就是利用Socket與服務(wù)器通信。于是這兩天看了看Silverlight下的Socket通信，在此將學(xué)習(xí)的心得和實(shí)現(xiàn)過程作一個(gè)記錄，以供相互學(xué)習(xí)和交流。

園子里關(guān)于這方面的內(nèi)容已經(jīng)有很多大神寫過了，這里小小的推薦一下：

http://www.cnblogs.com/webabcd/archive/2008/12/22/1359551.html

因此本文的重點(diǎn)知識(shí)說一下具體實(shí)現(xiàn)的過程，細(xì)節(jié)和原理性的東西不會(huì)太多，因?yàn)楸救艘彩切率?，所以就不賣弄了。之前說到和地圖結(jié)合，所以本文的后續(xù)工作將會(huì)把Silverlight的Socket通信與ArcGIS 的地圖結(jié)合，來實(shí)現(xiàn)一個(gè)小小的功能，而本篇?jiǎng)t主要關(guān)于Socket的實(shí)現(xiàn)過程。下面就進(jìn)入正題吧。

一.Silverlight的Socket通信和控制臺(tái)、WinForm下的Socket通信有很大的區(qū)別。

對(duì)于后兩者的Socket通信，其過程就是開啟端口，綁定端口，監(jiān)聽端口，連接，接收數(shù)據(jù)，發(fā)送數(shù)據(jù)。

而在Silverlight中則不太一樣，在Silverlight中，首先是Silverlight客戶端自動(dòng)向943端口的服務(wù)器端發(fā)送一個(gè)“<policy-file-request/>”的語句請(qǐng)求，然后服務(wù)器端向客戶端發(fā)送策略文件：

clientaccesspolicy.xml，例如：

<?xml version="1.0" encoding="utf-8" ?> 
<access-policy> 
  <cross-domain-access> 
    <policy> 
      <allow-from> 
        <domain uri="*"/> 
      </allow-from> 
      <grant-to> 
        <socket-resource port="4502-4534" protocol="tcp"/> 
      </grant-to> 
    </policy> 
  </cross-domain-access> 
</access-policy> 

發(fā)送之后，才允許和服務(wù)器進(jìn)行Socket通信，之后的過程則都是一樣。

二、服務(wù)器端

2.1、Silverligh中發(fā)送策略文件服務(wù)

上面說到，Silverlight中，服務(wù)器端會(huì)向客戶端發(fā)送策略文件，然后才能開始Socket通信，下面給出服務(wù)器端的發(fā)送策略文件服務(wù)的代碼，該代碼是在網(wǎng)上找的，是別人已經(jīng)寫好的一個(gè)類，所以在編寫Silverlight 的Socket通信程序時(shí)，只要添加這個(gè)類就好了，代碼如下：

using System;  
using System.Net.Sockets;  
using System.Net;  
using System.Threading;  
using System.IO;  
using System.Windows.Forms;  
 
namespace WindowsServer  
{  
    class PolicySocketServer  
    {  
        TcpListener _Listener = null;  
        TcpClient _Client = null;  
        static ManualResetEvent _TcpClientConnected = new ManualResetEvent(false);  
        const string _PolicyRequestString = "<policy-file-request/>";  
        int _ReceivedLength = 0;  
        byte[] _Policy = null;  
        byte[] _ReceiveBuffer = null;  
 
        private void InitializeData()  
        {  
            string policyFile = Path.Combine(Application.StartupPath, "clientaccesspolicy.xml");  
            using (FileStream fs = new FileStream(policyFile, FileMode.Open))  
            {  
                _Policy = new byte[fs.Length];  
                fs.Read(_Policy, 0, _Policy.Length);  
            }  
            _ReceiveBuffer = new byte[_PolicyRequestString.Length];  
        }  
        public void StartSocketServer()  
        {  
            InitializeData();  
 
            try  
            {  
                _Listener = new TcpListener(IPAddress.Any, 943);  
                _Listener.Start();  
                while (true)  
                {  
                    _TcpClientConnected.Reset();  
                    _Listener.BeginAcceptTcpClient(new AsyncCallback(OnBeginAccept), null);  
                    _TcpClientConnected.WaitOne();  
                }  
            }  
            catch (Exception)  
            {  
            }  
        }  
 
        private void OnBeginAccept(IAsyncResult ar)  
        {  
            _Client = _Listener.EndAcceptTcpClient(ar);  
            _Client.Client.BeginReceive(_ReceiveBuffer, 0, _PolicyRequestString.Length, SocketFlags.None,  
                new AsyncCallback(OnReceiveComplete), null);  
        }  
 
        private void OnReceiveComplete(IAsyncResult ar)  
        {  
            try  
            {  
                _ReceivedLength += _Client.Client.EndReceive(ar);  
                if (_ReceivedLength < _PolicyRequestString.Length)  
                {  
                    _Client.Client.BeginReceive(_ReceiveBuffer, _ReceivedLength,  
                        _PolicyRequestString.Length - _ReceivedLength,  
                        SocketFlags.None, new AsyncCallback(OnReceiveComplete), null);  
                    return;  
                }  
                string request = System.Text.Encoding.UTF8.GetString(_ReceiveBuffer, 0, _ReceivedLength);  
                if (StringComparer.InvariantCultureIgnoreCase.Compare(request, _PolicyRequestString) != 0)  
                {  
                    _Client.Client.Close();  
                    return;  
                }  
                _Client.Client.BeginSend(_Policy, 0, _Policy.Length, SocketFlags.None,  
                    new AsyncCallback(OnSendComplete), null);  
            }  
            catch (Exception)  
            {  
                _Client.Client.Close();  
            }  
            _ReceivedLength = 0;  
            _TcpClientConnected.Set(); //Allow waiting thread to proceed   
        }  
 
        private void OnSendComplete(IAsyncResult ar)  
        {  
            try  
            {  
                _Client.Client.EndSendFile(ar);  
            }  
            catch (Exception)  
            {  
            }  
            finally  
            {  
                _Client.Client.Close();  
            }  
        }   
    }  
} 

2.2、啟動(dòng)策略文件服務(wù)，聲明Socket，監(jiān)聽端口，接收數(shù)據(jù)，發(fā)送數(shù)據(jù)。

啟動(dòng)策略文件服務(wù)

#region Start The Policy Server 驗(yàn)證策略文件  
            PolicySocketServer StartPolicyServer = new PolicySocketServer();  
            Thread th = new Thread(new ThreadStart(StartPolicyServer.StartSocketServer));  
            th.IsBackground = true;  
            th.Start();  
            #endregion 

聲明Socket，綁定端口，開始監(jiān)聽

private void StartButton_Click(object sender, EventArgs e)  
        {//創(chuàng)建Socket  
            listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);  
            //獲取主機(jī)信息  
            IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());  
 
            //把IP和端口轉(zhuǎn)換化為IPEndPoint實(shí)例,端口號(hào)取4530  
            //Win7 中開啟了IPV6的地址，因此0,1對(duì)應(yīng)的是IPV6的地址，2，3對(duì)應(yīng)IPV4地址，3對(duì)應(yīng)本機(jī)的IP地址  
            //XP中沒有開啟IPV6  
            HostIPTextBox.Text = ipHostInfo.AddressList[3].ToString();  
 
            if (!string.IsNullOrEmpty(PortTextBox.Text))  
            {  
                //獲取端口號(hào)  
                int port = Convert.ToInt32(PortTextBox.Text.Trim());  
                //獲得本機(jī)的IP地址  
                localEP = new IPEndPoint(ipHostInfo.AddressList[3], port);  
            }  
            else  
            {  
               //默認(rèn)4530端口  
                ipAddress = IPAddress.Parse("127.0.0.1");  
                localEP = new IPEndPoint(ipHostInfo.AddressList[3], 4530);  
            }  
 
            try  
            {  
                //綁定指定的終結(jié)點(diǎn)  
                listener.Bind(localEP);  
                //開始監(jiān)聽  
                listener.Listen(10);  
                //一直循環(huán)接收客戶端的消息，開啟監(jiān)聽端口線程  
                ThreadStart threadwatchStart = new ThreadStart(WatchConnecting);  
                threadWatch = new Thread(threadwatchStart);  
                threadWatch.IsBackground = true;  
                threadWatch.Start();  
            }  
            catch (Exception ex)  
            {  
                MessageBox.Show(ex.Data.ToString());  
            }  
        } 

連接端口，接收數(shù)據(jù)

private void WatchConnecting()  
        {  
            ChangeStatue("等待Silverlight客戶端連接.....");  
            while (true)  //持續(xù)不斷監(jiān)聽客戶端發(fā)來的請(qǐng)求    
            {  
                listener.BeginAccept(AcceptCallBack, listener);  
                _flipFlop.WaitOne();  
            }  
        } 

private  void AcceptCallBack(IAsyncResult asyresult)  
        {  
            Socket listener = (Socket)asyresult.AsyncState;  
            Socket socket = listener.EndAccept(asyresult);  
            ChangeStatue("連接到Silverlight客戶端....");  
            _flipFlop.Set();  
            var state = new StateObject();  
            state.Socket = socket;  
            socket.BeginReceive(state.Buffer, 0, StateObject.BufferSize, 0, ReciverCallBack, state);  
        } 

private void ReciverCallBack(IAsyncResult asyResult)  
        {  
            StateObject state = (StateObject)asyResult.AsyncState;  
            Socket socket = state.Socket;  
            int read = socket.EndReceive(asyResult);  
            if (read > 0)  
            {  
                string chunk = Encoding.UTF8.GetString(state.Buffer, 0, read);  
                state.StringBuilder.Append(chunk);  
                if (state.StringBuilder.Length > 0)  
                {  
                    string result = state.StringBuilder.ToString();  
                    ChangeStatue("成功接收到消息："+result);  
                    ChangeReciveText(result);  
                    Send(socket, SendTextBox.Text);  
                    AddListItems("接收消息："+result+"\n");  
                    AddListItems("發(fā)送消息：" + SendTextBox.Text + "\n");  
                }  
            }  
        } 

發(fā)送數(shù)據(jù)

private void Send(Socket handler, String data)  
        {  
            byte[] byteData = Encoding.UTF8.GetBytes(data);  
            handler.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallBack), handler);  
        }  
 
        private void SendCallBack(IAsyncResult asyResult)  
        {  
            try  
            {  
                Socket handler = (Socket)asyResult.AsyncState;  
                int byteSent = handler.EndSend(asyResult);  
                if (byteSent > 0)  
                {  
                    ChangeStatue("發(fā)送數(shù)據(jù)成功！");  
                }  
            }  
            catch (Exception ex)  
            {  
                MessageBox.Show(ex.Data.ToString());  
            }  
        } 

StateObject類：

public class StateObject  
    {  
        public Socket Socket;  
        public StringBuilder StringBuilder = new StringBuilder();  
        public const int BufferSize = 1024;  
        public byte[] Buffer = new byte[BufferSize];  
        public int TotalSize;  
    } 

客戶端：

和服務(wù)器端類似，客戶端的操作包括：聲明Socket，指定服務(wù)器地址和端口，連接到指定的服務(wù)器端口，發(fā)送數(shù)據(jù)，接收數(shù)據(jù)。

下面是具體的實(shí)現(xiàn)代碼：

聲明Socket

private Socket socket; 

指定服務(wù)器地址和端口，開始連接

private void SendButton_Click(object sender, RoutedEventArgs e)  
        {  
            if(string.IsNullOrEmpty(IPTextBox.Text)||string.IsNullOrEmpty(PortTextBox.Text))  
            {  
                MessageBox.Show ("請(qǐng)輸入主機(jī)IP地址和端口號(hào)！");  
                return;  
            }  
            //ip地址  
            string host=IPTextBox.Text.Trim();  
            //端口號(hào)  
            int port=Convert.ToInt32(PortTextBox.Text.Trim());  
            //建立終結(jié)點(diǎn)對(duì)象  
            DnsEndPoint hostEntry=new DnsEndPoint(host,port);  
            //創(chuàng)建一個(gè)Socket對(duì)象  
            socket=new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);  
            //創(chuàng)建Socket異步事件參數(shù)  
            SocketAsyncEventArgs socketEventArg=new SocketAsyncEventArgs ();  
            //將消息轉(zhuǎn)化為發(fā)送的byte[]格式  
            byte[]buffer=Encoding.UTF8.GetBytes(MessageTextBox.Text);  
            //注冊(cè)Socket完成事件  
            socketEventArg.Completed+=new EventHandler<SocketAsyncEventArgs>(socketEventArg_Completed);  
            //設(shè)置Socket異步事件遠(yuǎn)程終結(jié)點(diǎn)  
            socketEventArg.RemoteEndPoint=hostEntry;  
            //將定義好的Socket對(duì)象賦值給Socket異步事件參數(shù)的運(yùn)行實(shí)例屬性  
            socketEventArg.UserToken = buffer;  
            try  
            {  
                socket.ConnectAsync(socketEventArg);  
            }  
            catch(SocketException ex)  
            {  
                throw new SocketException((int)ex.ErrorCode);  
            }  
        } 

向服務(wù)器發(fā)送數(shù)據(jù)，并接受服務(wù)器回復(fù)的消息。

private void socketEventArg_Completed(object sender, SocketAsyncEventArgs e)  
        {  
           //檢查是否發(fā)送出錯(cuò)  
            if (e.SocketError != SocketError.Success)  
            {  
                if (e.SocketError == SocketError.ConnectionAborted)  
                {  
                    Dispatcher.BeginInvoke(() => MessageBox.Show("連接超時(shí)....請(qǐng)重試！"));  
                }  
                else if (e.SocketError == SocketError.ConnectionRefused)  
                {  
                    Dispatcher.BeginInvoke(() => MessageBox.Show("無法連接到服務(wù)器端："+e.SocketError));  
                }else  
                {  
                    Dispatcher.BeginInvoke(() => MessageBox.Show("出錯(cuò)了！"+e.SocketError));  
                }  
                return;  
            }  
           //如果連接上，則發(fā)送數(shù)據(jù)  
            if (e.LastOperation == SocketAsyncOperation.Connect)  
            {  
                    byte[] userbytes = (byte[])e.UserToken;  
                    e.SetBuffer(userbytes, 0, userbytes.Length);  
                    socket.SendAsync(e);  
                      
            }//如果已發(fā)送數(shù)據(jù)，則開始接收服務(wù)器回復(fù)的消息  
            else if (e.LastOperation == SocketAsyncOperation.Send)  
            {  
                Dispatcher.BeginInvoke(() => 
                {  
                    listBox1.Items.Add("客戶端在" + DateTime.Now.ToShortTimeString() + "，發(fā)送消息：" + MessageTextBox.Text);  
                });  
                byte[] userbytes = new byte[1024];  
                e.SetBuffer(userbytes, 0, userbytes.Length);  
                socket.ReceiveAsync(e);  
            }//接收服務(wù)器數(shù)據(jù)  
            else if (e.LastOperation == SocketAsyncOperation.Receive)  
            {  
                string RecevieStr = Encoding.UTF8.GetString(e.Buffer, 0, e.Buffer.Length).Replace("\0", "");  
                Dispatcher.BeginInvoke(() => 
                {  
                    listBox1.Items.Add("服務(wù)器在" + DateTime.Now.ToShortTimeString() + "，回復(fù)消息：" + RecevieStr);  
                });  
                socket.Close();  
            }  
        } 

xaml代碼：

<UserControl 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    xmlns:esri="http://schemas.esri.com/arcgis/client/2009" x:Class="SilverlightSocket.MainPage" 
    mc:Ignorable="d" 
    d:DesignHeight="417" d:DesignWidth="530"> 
 
    <Grid x:Name="LayoutRoot" Background="White"> 
        <Grid.ColumnDefinitions> 
            <ColumnDefinition Width="0.868*"/> 
            <ColumnDefinition Width="0.135*"/> 
        </Grid.ColumnDefinitions> 
        <Grid.RowDefinitions> 
            <RowDefinition/> 
        </Grid.RowDefinitions> 
        <esri:Map Background="White" WrapAround="True" Grid.ColumnSpan="2"> 
            <esri:ArcGISTiledMapServiceLayer Url="http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"/> 
        </esri:Map> 
        <StackPanel Grid.Column="1" Background="#7F094870"> 
            <StackPanel.Effect> 
                <DropShadowEffect/> 
            </StackPanel.Effect> 
            <TextBlock x:Name="textBlock1" Text="主機(jī)IP" Grid.Column="1" Margin="5,5,0,0" Foreground="#FFE7D4E3" FontWeight="Bold" /> 
            <TextBox x:Name="IPTextBox" Text="169.254.57.67" Grid.Column="1" d:LayoutOverrides="Width" Margin="5,5,0,0" HorizontalAlignment="Left"/> 
            <TextBlock x:Name="textBlock2" Text="端口號(hào)" Grid.Column="1" Margin="5,5,0,0" Foreground="#FFE7D4E3" FontWeight="Bold" /> 
            <TextBox x:Name="PortTextBox" Width="51" Text="4530" Grid.Column="1" Margin="5,5,0,0" HorizontalAlignment="Left"/> 
            <TextBlock  x:Name="textBlock4" Text="消息記錄：" Height="23" Grid.Column="1" Margin="5,5,0,0" Foreground="#FFE7D4E3" FontWeight="Bold" /> 
            <ListBox  x:Name="listBox1" Grid.Column="1" Margin="5,5,0,0" Height="150" /> 
            <TextBlock x:Name="textBlock3" Text="發(fā)送信息內(nèi)容" Height="16" Grid.Column="1" d:LayoutOverrides="Width" Margin="5,5,0,0" Foreground="#FFE7D4E3" FontWeight="Bold" /> 
            <TextBox x:Name="MessageTextBox" Grid.Column="1" Height="50" Margin="5,5,0,0" /> 
            <Button Content="發(fā)送" Height="23" x:Name="SendButton" Grid.Column="1" Margin="5,5,0,0" /> 
            <Button Content="清空" Height="23" x:Name="ClearButton" Grid.Column="1" Margin="5,5,0,0" /> 
        </StackPanel> 
    </Grid> 
</UserControl> 

最后效果示意圖：

服務(wù)器端：

Silverlight客戶端：

后續(xù)工作中將結(jié)合地圖來實(shí)現(xiàn)模擬實(shí)時(shí)位置的顯示功能。。。。

原文鏈接：http://www.cnblogs.com/potential/archive/2013/01/23/2873035.html