之前因为项目的关系,涉及到与服务器实时通信,比如通过GPRS将GPS的位置信息等信息发送到服务器,然后再转发给Silverlight应用程序,最后在地图上标示出实时的地理位置,查了查相关的资料,网上给出的比较好的方法就是利用Socket与服务器通信。于是这两天看了看Silverlight下的Socket通信,在此将学习的心得和实现过程作一个记录,以供相互学习和交流。
园子里关于这方面的内容已经有很多大神写过了,这里小小的推荐一下:
http://www.cnblogs.com/webabcd/archive/2008/12/22/1359551.html
因此本文的重点知识说一下具体实现的过程,细节和原理性的东西不会太多,因为本人也是新手,所以就不卖弄了。之前说到和地图结合,所以本文的后续工作将会把Silverlight的Socket通信与ArcGIS 的地图结合,来实现一个小小的功能,而本篇则主要关于Socket的实现过程。下面就进入正题吧。
一.Silverlight的Socket通信和控制台、WinForm下的Socket通信有很大的区别。
对于后两者的Socket通信,其过程就是开启端口,绑定端口,监听端口,连接,接收数据,发送数据。
而在Silverlight中则不太一样,在Silverlight中,首先是Silverlight客户端自动向943端口的服务器端发送一个“<policy-file-request/>”的语句请求,然后服务器端向客户端发送策略文件:
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>
发送之后,才允许和服务器进行Socket通信,之后的过程则都是一样。
二、服务器端
2.1、Silverligh中发送策略文件服务
上面说到,Silverlight中,服务器端会向客户端发送策略文件,然后才能开始Socket通信,下面给出服务器端的发送策略文件服务的代码,该代码是在网上找的,是别人已经写好的一个类,所以在编写Silverlight 的Socket通信程序时,只要添加这个类就好了,代码如下:
- 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、启动策略文件服务,声明Socket,监听端口,接收数据,发送数据。
启动策略文件服务
- #region Start The Policy Server 验证策略文件
- PolicySocketServer StartPolicyServer = new PolicySocketServer();
- Thread th = new Thread(new ThreadStart(StartPolicyServer.StartSocketServer));
- th.IsBackground = true;
- th.Start();
- #endregion
声明Socket,绑定端口,开始监听
- private void StartButton_Click(object sender, EventArgs e)
- {//创建Socket
- listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
- //获取主机信息
- IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());
- //把IP和端口转换化为IPEndPoint实例,端口号取4530
- //Win7 中开启了IPV6的地址,因此0,1对应的是IPV6的地址,2,3对应IPV4地址,3对应本机的IP地址
- //XP中没有开启IPV6
- HostIPTextBox.Text = ipHostInfo.AddressList[3].ToString();
- if (!string.IsNullOrEmpty(PortTextBox.Text))
- {
- //获取端口号
- int port = Convert.ToInt32(PortTextBox.Text.Trim());
- //获得本机的IP地址
- localEP = new IPEndPoint(ipHostInfo.AddressList[3], port);
- }
- else
- {
- //默认4530端口
- ipAddress = IPAddress.Parse("127.0.0.1");
- localEP = new IPEndPoint(ipHostInfo.AddressList[3], 4530);
- }
- try
- {
- //绑定指定的终结点
- listener.Bind(localEP);
- //开始监听
- listener.Listen(10);
- //一直循环接收客户端的消息,开启监听端口线程
- ThreadStart threadwatchStart = new ThreadStart(WatchConnecting);
- threadWatch = new Thread(threadwatchStart);
- threadWatch.IsBackground = true;
- threadWatch.Start();
- }
- catch (Exception ex)
- {
- MessageBox.Show(ex.Data.ToString());
- }
- }
连接端口,接收数据
- private void WatchConnecting()
- {
- ChangeStatue("等待Silverlight客户端连接.....");
- while (true) //持续不断监听客户端发来的请求
- {
- listener.BeginAccept(AcceptCallBack, listener);
- _flipFlop.WaitOne();
- }
- }
- private void AcceptCallBack(IAsyncResult asyresult)
- {
- Socket listener = (Socket)asyresult.AsyncState;
- Socket socket = listener.EndAccept(asyresult);
- ChangeStatue("连接到Silverlight客户端....");
- _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("发送消息:" + SendTextBox.Text + "\n");
- }
- }
- }
发送数据
- 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("发送数据成功!");
- }
- }
- catch (Exception ex)
- {
- MessageBox.Show(ex.Data.ToString());
- }
- }
StateObject类:
- 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;
- }
客户端:
和服务器端类似,客户端的操作包括:声明Socket,指定服务器地址和端口,连接到指定的服务器端口,发送数据,接收数据。
下面是具体的实现代码:
声明Socket
- private Socket socket;
指定服务器地址和端口,开始连接
- private void SendButton_Click(object sender, RoutedEventArgs e)
- {
- if(string.IsNullOrEmpty(IPTextBox.Text)||string.IsNullOrEmpty(PortTextBox.Text))
- {
- MessageBox.Show ("请输入主机IP地址和端口号!");
- return;
- }
- //ip地址
- string host=IPTextBox.Text.Trim();
- //端口号
- int port=Convert.ToInt32(PortTextBox.Text.Trim());
- //建立终结点对象
- DnsEndPoint hostEntry=new DnsEndPoint(host,port);
- //创建一个Socket对象
- socket=new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
- //创建Socket异步事件参数
- SocketAsyncEventArgs socketEventArg=new SocketAsyncEventArgs ();
- //将消息转化为发送的byte[]格式
- byte[]buffer=Encoding.UTF8.GetBytes(MessageTextBox.Text);
- //注册Socket完成事件
- socketEventArg.Completed+=new EventHandler<SocketAsyncEventArgs>(socketEventArg_Completed);
- //设置Socket异步事件远程终结点
- socketEventArg.RemoteEndPoint=hostEntry;
- //将定义好的Socket对象赋值给Socket异步事件参数的运行实例属性
- socketEventArg.UserToken = buffer;
- try
- {
- socket.ConnectAsync(socketEventArg);
- }
- catch(SocketException ex)
- {
- throw new SocketException((int)ex.ErrorCode);
- }
- }
向服务器发送数据,并接受服务器回复的消息。
- private void socketEventArg_Completed(object sender, SocketAsyncEventArgs e)
- {
- //检查是否发送出错
- if (e.SocketError != SocketError.Success)
- {
- if (e.SocketError == SocketError.ConnectionAborted)
- {
- Dispatcher.BeginInvoke(() => MessageBox.Show("连接超时....请重试!"));
- }
- else if (e.SocketError == SocketError.ConnectionRefused)
- {
- Dispatcher.BeginInvoke(() => MessageBox.Show("无法连接到服务器端:"+e.SocketError));
- }else
- {
- Dispatcher.BeginInvoke(() => MessageBox.Show("出错了!"+e.SocketError));
- }
- return;
- }
- //如果连接上,则发送数据
- if (e.LastOperation == SocketAsyncOperation.Connect)
- {
- byte[] userbytes = (byte[])e.UserToken;
- e.SetBuffer(userbytes, 0, userbytes.Length);
- socket.SendAsync(e);
- }//如果已发送数据,则开始接收服务器回复的消息
- else if (e.LastOperation == SocketAsyncOperation.Send)
- {
- Dispatcher.BeginInvoke(() =>
- {
- listBox1.Items.Add("客户端在" + DateTime.Now.ToShortTimeString() + ",发送消息:" + MessageTextBox.Text);
- });
- byte[] userbytes = new byte[1024];
- e.SetBuffer(userbytes, 0, userbytes.Length);
- socket.ReceiveAsync(e);
- }//接收服务器数据
- else if (e.LastOperation == SocketAsyncOperation.Receive)
- {
- string RecevieStr = Encoding.UTF8.GetString(e.Buffer, 0, e.Buffer.Length).Replace("\0", "");
- Dispatcher.BeginInvoke(() =>
- {
- listBox1.Items.Add("服务器在" + DateTime.Now.ToShortTimeString() + ",回复消息:" + RecevieStr);
- });
- socket.Close();
- }
- }
xaml代码:
- <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="主机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="端口号" 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="消息记录:" 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="发送信息内容" 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="发送" 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>
最后效果示意图:
服务器端:
Silverlight客户端:
后续工作中将结合地图来实现模拟实时位置的显示功能。。。。
原文链接:http://www.cnblogs.com/potential/archive/2013/01/23/2873035.html