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C#完整的通信代码（点对点，点对多，同步，异步，UDP，TCP)

發布時間：2023/12/18 C# 28 豆豆

生活随笔收集整理的這篇文章主要介紹了 C#完整的通信代码（点对点，点对多，同步，异步，UDP，TCP) 小編覺得挺不錯的,現在分享給大家,幫大家做個參考.

C# code

namespace UDPServer

{

??? class Program

??? {

??????? static void Main(string[] args)

??????? {

??????????? int recv;

??????????? byte[] data = new byte[1024];

??????????? //構建TCP 服務器

??????????? //得到本機IP，設置TCP端口號?????????

??????????? IPEndPoint ipep = new IPEndPoint(IPAddress.Any , 8001);

??????????? Socket newsock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram , ProtocolType.Udp);

??????????? //綁定網絡地址

??????????? newsock.Bind(ipep);

??????????? Console.WriteLine("This is a Server, host name is {0}",Dns.GetHostName());

??????????? //等待客戶機連接

??????????? Console.WriteLine("Waiting for a client...");

??????????? //得到客戶機IP

??????????? IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);

??????????? EndPoint Remote = (EndPoint)(sender);

??????????? recv = newsock.ReceiveFrom(data, ref Remote);

??????????? Console .WriteLine ("Message received from {0}: ", Remote.ToString ());

??????????? Console .WriteLine (Encoding .ASCII .GetString (data ,0,recv ));

??????????? //客戶機連接成功后，發送歡迎信息

??????????? string welcome = "Welcome ! ";

??????????? //字符串與字節數組相互轉換

??????????? data? = Encoding .ASCII .GetBytes (welcome );

??????????? //發送信息

??????????? newsock .SendTo (data ,data.Length ,SocketFlags .None ,Remote );

??????????? while (true )

??????????? {

??????????????? data =new byte [1024];

??????????????? //發送接受信息

??????????????? recv =newsock.ReceiveFrom(data ,ref Remote);

??????????????? Console .WriteLine (Encoding .ASCII .GetString (data ,0,recv));

??????????????? newsock .SendTo (data ,recv ,SocketFlags .None ,Remote );

??????????? }

??????? }

??? }

C# code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace UDPClient
{
??? class Program
??? {
??????? static void Main(string[] args)
??????? {
??????????? byte[] data = new byte[1024];
??????????? string input ,stringData;
??????????? //構建TCP 服務器
??????????? Console.WriteLine("This is a Client, host name is {0}", Dns.GetHostName());
??????????? //設置服務IP，設置TCP端口號
??????????? IPEndPoint ipep = new IPEndPoint(IPAddress .Parse ("127.0.0.1") , 8001);
??????????? //定義網絡類型，數據連接類型和網絡協議UDP
??????????? Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
??????????? string welcome = "Hello! ";
??????????? data = Encoding.ASCII.GetBytes(welcome);
??????????? server.SendTo(data, data.Length, SocketFlags.None, ipep);
??????????? IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
??????????? EndPoint Remote = (EndPoint)sender;
??????????? data = new byte[1024];
??????????? int recv = server.ReceiveFrom(data, ref Remote);
??????????? Console.WriteLine("Message received from {0}: ", Remote.ToString());
??????????? Console.WriteLine(Encoding .ASCII .GetString (data,0,recv));
??????????? while (true)
??????????? {
??????????????? input = Console .ReadLine ();
??????????????? if (input =="exit")
??????????????????? break ;
??????????????? server .SendTo (Encoding .ASCII .GetBytes (input ),Remote );
??????????????? data = new byte [1024];
??????????????? recv = server.ReceiveFrom(data, ref Remote);
??????????????? stringData = Encoding.ASCII.GetString(data, 0, recv);
??????????????? Console.WriteLine(stringData);
??????????? }
??????????? Console .WriteLine ("Stopping Client.");
??????????? server .Close ();????????????
??????? }
??????? }
??? }

C# code
TCPClient
TCPClient 類提供了一種使用 TCP 協議連接到某個端點的簡化方法。它還通過 NetworkStream 對象展現在連接過程中讀取或寫入的數據。請參見下面從 QuickStart 文檔中摘錄的日期/時間客戶機示例。
使用 C# 編寫
using System;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Text;
class Client
{
public static void Main(String[] args)
{
TCPClient tcpc = new TCPClient();
Byte[] read = new Byte[32];
if (args.Length != 1)
{
Console.WriteLine(“請在命令行中指定服務器名稱”);
return;
}
String server = args[0];
// 驗證服務器是否存在
if (DNS.GetHostByName(server) == null)
{
Console.WriteLine(“找不到服務器：” + 服務器);
return;
}
// 嘗試連接到服務器
if (tcpc.Connect(server, 13) == -1)
{
Console.WriteLine(“無法連接到服務器：” + 服務器);
return;
}
// 獲取流
Stream s = tcpc.GetStream();
// 讀取流并將它轉換為 ASCII 碼形式
int bytes = s.Read(read, 0, read.Length);
String Time = Encoding.ASCII.GetString(read);
// 顯示數據
Console.WriteLine(“已接收到的” + 字節 + “字節”);
Console.WriteLine(“當前日期和時間是：” + 時間);
tcpc.Close();
}
}
TCPListener
TCPListener 類便于在來自某個客戶機的 TCP 連接的特定套接字上進行偵聽的工作。請參見下面包括在 QuickStart 文檔中的日期/時間服務器示例。
使用 C# 編寫
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
class Server
{
public static void Main()
{
DateTime now;
String strDateLine;
Encoding ASCII = Encoding.ASCII;
// 在端口 13 進行偵聽
TCPListener tcpl = new TCPListener(13);
tcpl.Start();
Console.WriteLine(“正在等待客戶進行連接”);
Console.WriteLine(“請按 Ctrl+c 退出...”);
while (true)
{
// 接收會阻塞，直到有人連接上
Socket s = tcpl.Accept();
// 獲取當前的日期和時間并將它連接成一個字符串
now = DateTime.Now;
strDateLine = now.ToShortDateString() + " " +
now.ToLongTimeString();
// 將該字符串轉換成一個字節數組并發送它
Byte[] byteDateLine =
ASCII.GetBytes(strDateLine.ToCharArray());
s.Send(byteDateLine, byteDateLine.Length, 0);
Console.WriteLine(“發送” + strDateLine);
}
}
}

#region "Download: File transfer FROM ftp server"?
??????? /// <summary>?
??????? /// Copy a file from FTP server to local?
??????? /// </summary>?
??????? /// <param name="sourceFilename">Target filename, if required </param>?
??????? /// <param name="localFilename">Full path of the local file </param>?
??????? /// <returns> </returns>?
??????? /// <remarks>Target can be blank (use same filename), or just a filename?
??????? /// (assumes current directory) or a full path and filename </remarks>?
??????? public bool Download(string sourceFilename, string localFilename, bool PermitOverwrite)?
??????? {?
??????????? //2. determine target file?
??????????? FileInfo fi = new FileInfo(localFilename);?
??????????? return this.Download(sourceFilename, fi, PermitOverwrite);?
??????? }?
??????? //Version taking an FtpFileInfo?
??????? public bool Download(FtpFileInfo file, string localFilename, bool permitOverwrite)?
??????? {?
??????????? return this.Download(file.FullName, localFilename, permitOverwrite);?
??????? }?
??????? //Another version taking FtpFileInfo and FileInfo?
??????? public bool Download(FtpFileInfo file, FileInfo localFI, bool permitOverwrite)?
??????? {?
??????????? return this.Download(file.FullName, localFI, permitOverwrite);?
??????? }?
??????? //Version taking string/FileInfo?
??????? public bool Download(string sourceFilename, FileInfo targetFI, bool permitOverwrite)?
??????? {?
??????????? //1. check target?
??????????? if (targetFI.Exists && !(permitOverwrite))?
??????????? {?
??????????????? throw (new ApplicationException("Target file already exists"));?
??????????? }?
??????????? //2. check source?
??????????? string target;?
??????????? if (sourceFilename.Trim() == "")?
??????????? {?
??????????????? throw (new ApplicationException("File not specified"));?
??????????? }?
??????????? else if (sourceFilename.Contains("/"))?
??????????? {?
??????????????? //treat as a full path?
??????????????? target = AdjustDir(sourceFilename);?
??????????? }?
??????????? else?
??????????? {?
??????????????? //treat as filename only, use current directory?
??????????????? target = CurrentDirectory + sourceFilename;?
??????????? }?
??????????? string URI = Hostname + target;?
??????????? //3. perform copy?
??????????? System.Net.FtpWebRequest ftp = GetRequest(URI);?
??????????? //Set request to download a file in binary mode?
??????????? ftp.Method = System.Net.WebRequestMethods.Ftp.DownloadFile;?
??????????? ftp.UseBinary = true;?
??????????? //open request and get response stream?
??????????? using (FtpWebResponse response = (FtpWebResponse)ftp.GetResponse())?
??????????? {?
??????????????? using (Stream responseStream = response.GetResponseStream())?
??????????????? {?
??????????????????? //loop to read & write to file?
??????????????????? using (FileStream fs = targetFI.OpenWrite())?
??????????????????? {?
??????????????????????? try?
??????????????????????? {?
??????????????????????????? byte[] buffer = new byte[2048];?
??????????????????????????? int read = 0;?
??????????????????????????? do?
??????????????????????????? {?
??????????????????????????????? read = responseStream.Read(buffer, 0, buffer.Length);?
??????????????????????????????? fs.Write(buffer, 0, read);?
??????????????????????????? } while (!(read == 0));?
??????????????????????????? responseStream.Close();?
??????????????????????????? fs.Flush();?
??????????????????????????? fs.Close();?
??????????????????????? }?
??????????????????????? catch (Exception)?
??????????????????????? {?
??????????????????????????? //catch error and delete file only partially downloaded?
??????????????????????????? fs.Close();?
??????????????????????????? //delete target file as it's incomplete?
??????????????????????????? targetFI.Delete();?
??????????????????????????? throw;?
??????????????????????? }?
??????????????????? }?
??????????????????? responseStream.Close();?
??????????????? }?
??????????????? response.Close();?
??????????? }?
??????????? return true;?
??????? }?
??????? #endregion

簡單的UDP收發.?
發送?
C# code
??????????????????? try
??????????????????? {
??????????????????????? Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);? //向此網段發廣播包
????????????????????????? int UDPListenerPort = 8082;
??????????????????????? IPAddress broadcast = IPAddress.Parse("192.168.0.255"); //此處根據IP及子網掩碼改為相應的廣播IP
??????????????????????? string ts = "This is UPD string for sending";
??????????????????????? byte[] sendbuf = Encoding.ASCII.GetBytes(ts);
??????????????????????? IPEndPoint ep = new IPEndPoint(broadcast, UDPListenerPort);
??????????????????????? s.SendTo(sendbuf, ep);
??????????????????? }
??????????????????? catch (Exception e)
??????????????????? {}
接收?
C# code
?????????? UdpClient listener;
??????????? int UDPListenerPort = 8082;
??????????? IPEndPoint groupEP = new IPEndPoint(IPAddress.Any, UDPListenerPort);
??????????? try
??????????? {
??????????????? while (true)
??????????????? {
??????????????????? byte[] bytes = listener.Receive(ref groupEP);
??????????????????? string RecIP = groupEP.ToString().Substring(0, groupEP.ToString().IndexOf(":"));? //收到發送UPD端的IP
??????????????????? string RecStr = Encoding.ASCII.GetString(bytes, 0, bytes.Length);?? //收到的UPD字符串
??????????????? }
??????????? }
??????????? catch
??????????? {}

C# code?
TCPClient?
TCPClient 類提供了一種使用 TCP 協議連接到某個端點的簡化方法。它還通過 NetworkStream 對象展現在連接過程中讀取或寫入的數據。請參見下面從 QuickStart 文檔中摘錄的日期/時間客戶機示例。?
使用 C# 編寫?
using System;?
using System.Net;?
using System.Net.Sockets;?
using System.IO;?
using System.Text;?
class Client?
{?
public static void Main(String[] args)?
{?
TCPClient tcpc = new T…

來一個Remoting的:?
C# code
using System;?
namespace Remotable?
{?
??? public class RemotableType : MarshalByRefObject?
??? {?
??????? private string _internalString = "This is the RemotableType.";?
??????? public string StringMethod()?
??????? {?
??????????? return _internalString;?
??????? }?
??? }?
}?
using System;?
using System.Runtime.Remoting;?
namespace RemotingFirst?
{?
??? public class Listener?
??? {?
??????? public static void Main()?
??????? {?
??????????? RemotingConfiguration.Configure("Listener.exe.config");?
??????????? Console.WriteLine("Listening for requests. Press Enter to exit");?
??????????? Console.ReadLine();?
??????? }?
??? }?
}?
using System;?
using System.Runtime.Remoting;?
namespace Client?
{?
??? public class Client?
??? {?
??????? public static void Main()?
??????? {?
??????????? RemotingConfiguration.Configure("Client.exe.config");?
??????????? Remotable.RemotableType remoteObject = new Remotable.RemotableType();?
??????????? Console.WriteLine(remoteObject.StringMethod());?
??????? }?
??? }?
}?
Listener.exe.config?
<?xml version="1.0" encoding="utf-8" ?>?
<configuration>?
??? <system.runtime.remoting>?
????? <application>?
???????? <service>?
??????????? <wellknown??
?????????????? mode="Singleton"??
?????????????? type="Remotable.RemotableType, RemotableType"??
?????????????? objectUri="RemotableType.rem"?
??????????? />?
???????? </service>?
???????? <channels>?
??????????? <channel ref="http" port="8989"/>?
???????? </channels>?
????? </application>?
??? </system.runtime.remoting>?
</configuration>

實只要用到Socket聯接，基本上就得使用Thread，是交叉使用的。?
C#封裝的Socket用法基本上不算很復雜，只是不知道托管之后的Socket有沒有其他性能或者安全上的問題。?
在C#里面能找到的最底層的操作也就是socket了，概念不做解釋。?
程序模型如下：?
WinForm程序：啟動端口偵聽；監視Socket聯接情況；定期關閉不活動的聯接；?
Listener：處理Socket的Accept函數，偵聽新鏈接，建立新Thread來處理這些聯接（Connection）。?
Connection：處理具體的每一個聯接的會話。?
1：WinForm如何啟動一個新的線程來啟動Listener：?
????? //start the server?
??????? private void btn_startServer_Click(object sender, EventArgs e)?
??????? {?
??????????? //this.btn_startServer.Enabled = false;?
??????????? Thread _createServer = new Thread(new ThreadStart(WaitForConnect));?
??????????? _createServer.Start();?
??????? }?
??????? //wait all connections?
??????? private void WaitForConnect()?
??????? {?
??????????? SocketListener listener = new SocketListener(Convert.ToInt32(this.txt_port.Text));?
??????????? listener.StartListening();?
??????? }?
因為偵聽聯接是一個循環等待的函數，所以不可能在WinForm的線程里面直接執行，不然Winform也就是無法繼續任何操作了，所以才指定一個新的線程來執行這個函數，啟動偵聽循環。?
這一個新的線程是比較簡單的，基本上沒有啟動的參數，直接指定處理函數就可以了。?
2：Listener如何啟動循環偵聽，并且啟動新的帶有參數的線程來處理Socket聯接會話。?
先看如何建立偵聽：（StartListening函數）?
IPEndPoint localEndPoint = new IPEndPoint(_ipAddress, _port);?
??????? // Create a TCP/IP socket.?
??????? Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);?
??????????? // Bind the socket to the local endpoint and? listen for incoming connections.?
??????????? try?
??????????? {?
??????????????? listener.Bind(localEndPoint);?
??????????????? listener.Listen(20);//20 trucks?
??????????????? // Start listening for connections.?
??????????????? while (true)?
??????????????? {?
????????????????? // here will be suspended while waiting for a new connection.?
??????????????????? Socket connection = listener.Accept();?
??????????????????? Logger.Log("Connect", connection.RemoteEndPoint.ToString());//log it, new connection?
??????????????? ……?
????????? }?
??????? }……?
基本步驟比較簡單：?
建立本機的IPEndPoint對象，表示以本機為服務器，在指定端口偵聽；?
然后綁定到一個偵聽Socket上；?
進入while循環，等待新的聯接；?
如果有新的聯接，那么建立新的socket來對應這個聯接的會話。?
? 值得注意的就是這一句聯接代碼：listener.Accept()。執行這一句的時候，程序就在這個地方等待，直到有新的聯檢請求的時候程序才會執行下一句。這是同步執行，當然也可以異步執行。?
? 新的聯接Socket建立了（Accept之后），對于這些新的socket該怎么辦呢？他們依然是一個循環等待，所以依然需要建立新的Thread給這些Socket去處理會話（接收/發送消息），而這個Thread就要接收參數了。?
? Thread本身是不能接收參數的，為了讓它可以接收參數，可以采用定義新類，添加參數作為屬性的方法來解決。?
? 因為每一個Socket是一個Connection周期，所以我定義了這么一個類public class Connection。這個類至少有這樣一個構造函數public Connection(Socket socket); 之所以這么做，就是為了把Socket參數傳給這個Connection對象，然后好讓Listener啟動這個Thread的時候，Thread可以知道他正在處理哪一個Socket。?
??? 具體處理的方法：（在Listener的StartListening函數，ocket connection = listener.Accept();之后）?
??? Connection gpsCn = new Connection(connection);?
??????????????????? //each socket will be wait for data. keep the connection.?
??????????????????? Thread thread = new Thread(new ThreadStart(gpsCn.WaitForSendData));?
??????????????????? thread.Name = connection.RemoteEndPoint.ToString();?
??????????????????? thread.Start();?
如此一來，這個新的socket在Accept之后就在新的Thread中運行了。?
? 3：Connection的會話處理?
? 建立了新的Connection（也就是socket），遠程就可以和這個socket進行會話了，無非就是send和receive。?
? 現在先看看怎么寫的這個線程運行的Connection. WaitForSendData函數?
??? while (true)?
??????????? {?
??????????????? bytes = new byte[1024];?
??????????????? string data = "";?
??????????????? //systm will be waiting the msg of receive envet. like Accept();?
??????????????? //here will be suspended while waiting for socket income msg.?
??????????????? int bytesRec = this._connection.Receive(bytes);?
??????????????? _lastConnectTime = DateTime.Now;?
??????????????? if (bytesRec == 0)//close envent?
??????????????? {?
??????????????????? Logger.Log("Close Connection", _connection.RemoteEndPoint.ToString());?
??????????????????? break;?
??????????????? }?
??????????????? data += Encoding.ASCII.GetString(bytes, 0, bytesRec);?
??????????????? //…….handle your data.?
??????????? }?
可以看到這個處理的基本步驟如下：?
? 執行Receive函數，接收遠程socket發送的信息；?
? 把信息從字節轉換到string；?
? 處理該信息，然后進入下一個循環，繼續等待socket發送新的信息。?
值得注意的有幾個：?
? 1：Receive函數。這個函數和Listener的Accept函數類似。在這個地方等待執行，如果沒有新的消息，這個函數就不會執行下一句，一直等待。?
? 2：接收的是字節流，需要轉化成字符串?
? 3：判斷遠程關閉聯接的方式?
? 4：如果對方的消息非常大，還得循環接收這個data。?
4：如何管理這些聯接（thread）?
通過上邊的程序，基本上可以建立一個偵聽，并且處理聯接會話。但是如何管理這些thread呢？不然大量產生thread可是一個災難。?
管理的方法比較簡單，在Listener里面我定義了一個靜態的哈希表(static public Hashtable Connections=new Hashtable();)，存儲Connection實例和它對應的Thread實例。而connection中也加入了一個最后聯接時間的定義（private DateTime _lastConnectTime;）。在新鏈接建立的時候（Listener的Accept()之后）就把Connection實例和Thread實例存到哈希表中；在Connection的Receive的時候修改最后聯接時間。這樣我們就可以知道該Connection在哪里，并且會話是否活躍。?
然后在Winform程序里頭可以管理這些會話了，設置設置超時。

在網絡環境下，我們最感興趣的兩個命名空間是System.Net和 System.Net.Sockets。System.Net命名空間通常與較高程的操作有關，例如download或upload，試用HTTP和其他協議進行Web請求等等，而System.Net.Sockets命名空間所包含的類通常與較低程的操作有關。如果要直接使用Sockets或者 TCP/IP之類的協議，這個命名空間的類是非常有用的。?
　　在.Net中，System.Net.Sockets 命名空間為需要嚴密控制網絡訪問的開發人員提供了 Windows Sockets (Winsock) 接口的托管實現。System.Net 命名空間中的所有其他網絡訪問類都建立在該套接字Socket實現之上，如TCPClient、TCPListener 和 UDPClient 類封裝有關創建到 Internet 的 TCP 和 UDP 連接的詳細信息；NetworkStream類則提供用于網絡訪問的基礎數據流等，常見的許多Internet服務都可以見到Socket的蹤影，如 Telnet、Http、Email、Echo等，這些服務盡管通訊協議Protocol的定義不同，但是其基礎的傳輸都是采用的Socket。?
　　其實，Socket可以象流Stream一樣被視為一個數據通道，這個通道架設在應用程序端（客戶端）和遠程服務器端之間，而后，數據的讀取（接收）和寫入（發送）均針對這個通道來進行。?
　　可見，在應用程序端或者服務器端創建了Socket對象之后，就可以使用Send/SentTo方法將數據發送到連接的Socket,或者使用Receive/ReceiveFrom方法接收來自連接Socket的數據。?
　　針對Socket編程，.NET 框架的 Socket 類是 Winsock32 API 提供的套接字服務的托管代碼版本。其中為實現網絡編程提供了大量的方法，大多數情況下，Socket 類方法只是將數據封送到它們的本機 Win32 副本中并處理任何必要的安全檢查。如果你熟悉Winsock API函數，那么用Socket類編寫網絡程序會非常容易，當然，如果你不曾接觸過，也不會太困難，跟隨下面的解說，你會發覺使用Socket類開發 windows 網絡應用程序原來有規可尋，它們在大多數情況下遵循大致相同的步驟。?
　　在使用之前，你需要首先創建Socket對象的實例，這可以通過Socket類的構造方法來實現：?
public Socket(AddressFamily addressFamily,SocketType socketType,ProtocolType protocolType);?
　　其中，addressFamily 參數指定 Socket 使用的尋址方案，socketType 參數指定 Socket 的類型，protocolType 參數指定 Socket 使用的協議。?
　　下面的示例語句創建一個 Socket，它可用于在基于 TCP/IP 的網絡（如 Internet）上通訊。?
Socket temp = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);?
　　若要使用 UDP 而不是 TCP，需要更改協議類型，如下面的示例所示：?
Socket temp = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);?
　　一旦創建 Socket，在客戶端，你將可以通過Connect方法連接到指定的服務器，并通過Send/SendTo方法向遠程服務器發送數據，而后可以通過 Receive/ReceiveFrom從服務端接收數據；而在服務器端，你需要使用Bind方法綁定所指定的接口使Socket與一個本地終結點相聯，并通過Listen方法偵聽該接口上的請求，當偵聽到用戶端的連接時，調用Accept完成連接的操作，創建新的Socket以處理傳入的連接請求。使用完 Socket 后，記住使用 Shutdown 方法禁用 Socket，并使用 Close 方法關閉 Socket。?
　　可以看出，以上許多方法包含EndPoint類型的參數，在Internet中，TCP/IP 使用一個網絡地址和一個服務端口號來唯一標識設備。網絡地址標識網絡上的特定設備；端口號標識要連接到的該設備上的特定服務。網絡地址和服務端口的組合稱為終結點，在 .NET 框架中正是由 EndPoint 類表示這個終結點，它提供表示網絡資源或服務的抽象，用以標志網絡地址等信息。.Net同時也為每個受支持的地址族定義了 EndPoint 的子代；對于 IP 地址族，該類為 IPEndPoint。IPEndPoint 類包含應用程序連接到主機上的服務所需的主機和端口信息，通過組合服務的主機IP地址和端口號，IPEndPoint 類形成到服務的連接點。?
　　用到IPEndPoint類的時候就不可避免地涉及到計算機IP地址，System.Net命名空間中有兩種類可以得到IP地址實例：?
　　IPAddress類：IPAddress 類包含計算機在 IP 網絡上的地址。其Parse方法可將 IP 地址字符串轉換為 IPAddress 實例。下面的語句創建一個 IPAddress 實例：?
IPAddress myIP = IPAddress.Parse("192.168.0.1");?
　　Dns 類：向使用 TCP/IP Internet 服務的應用程序提供域名服務。其Resolve 方法查詢 DNS 服務器以將用戶友好的域名（如"host.mydomain.com"）映射到數字形式的 Internet 地址（如 192.168.0.1）。Resolve方法返回一個 IPHostEnty 實例，該實例包含所請求名稱的地址和別名的列表。大多數情況下，可以使用 AddressList 數組中返回的第一個地址。下面的代碼獲取一個 IPAddress 實例，該實例包含服務器 host.mydomain.com 的 IP 地址。?
IPHostEntry ipHostInfo = Dns.Resolve("host.mydomain.com ");?
IPAddress ipAddress = ipHostInfo.AddressList[0];?
　　你也可以使用GetHostName方法得到IPHostEntry實例：?
IPHosntEntry hostInfo=Dns.GetHostByName("host.mydomain.com ")?
　　在使用以上方法時，你將可能需要處理以下幾種異常：?
　　SocketException異常：訪問Socket時操作系統發生錯誤引發?
　　ArgumentNullException異常：參數為空引用引發?
　　ObjectDisposedException異常：Socket已經關閉引發?
　　在掌握上面得知識后，下面的代碼將該服務器主機（ host.mydomain.com的 IP 地址與端口號組合，以便為連接創建遠程終結點：?
IPEndPoint ipe = new IPEndPoint(ipAddress,11000);?
　　確定了遠程設備的地址并選擇了用于連接的端口后，應用程序可以嘗試建立與遠程設備的連接。下面的示例使用現有的 IPEndPoint 實例與遠程設備連接，并捕獲可能引發的異常：?
try?
{?
temp.Connect(ipe);//嘗試連接?
}?
//處理參數為空引用異常?
catch(ArgumentNullException ae)?
{?
Console.WriteLine("ArgumentNullException : {0}", ae.ToString());?
}?
//處理操作系統異常?
catch(SocketException se)?
{?
Console.WriteLine("SocketException : {0}", se.ToString());?
}?
　　需要知道的是：Socket 類支持兩種基本模式：同步和異步。其區別在于：在同步模式中，對執行網絡操作的函數（如 Send 和 Receive）的調用一直等到操作完成后才將控制返回給調用程序。在異步模式中，這些調用立即返回。?
綜合運用以上闡述的使用Visual C#進行Socket網絡程序開發的知識，下面的程序是一個簡單的Socket通訊實例，client向server發送一段測試字符串，server接收并顯示出來，給予client成功相應。?
//client端?
using System;?
using System.Text;?
using System.IO;?
using System.Net;?
using System.Net.Sockets;?
namespace socketsample?
{?
　class Class1?
　{?
　　static void Main()?
　　{?
　　　try?
　　　{?
　　　　int port = 2000;?
　　　　string host = "127.0.0.1";?
　　　　IPAddress ip = IPAddress.Parse(host);?
　　　　IPEndPoint ipe = new IPEndPoint(ip, port);?
　　　　Socket c = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);?
　　　　c.Connect(ipe);?
　　　　string sendStr = "hello!This is a socket test";?
　　　　byte[] bs = Encoding.ASCII.GetBytes(sendStr);?
　　　　c.Send(bs, bs.Length, 0);?
　　　　string recvStr = "";?
　　　　byte[] recvBytes = new byte[1024];?
　　　　int bytes;?
　　　　bytes = c.Receive(recvBytes, recvBytes.Length, 0);?
　　　　recvStr += Encoding.ASCII.GetString(recvBytes, 0, bytes);?
　　　　Console.WriteLine(recvStr);?
　　　　c.Close();?
　　　}?
　　　catch (ArgumentNullException e)?
　　　{?
　　　　Console.WriteLine("ArgumentNullException: {0}", e);?
　　　}?
　　　catch (SocketException e)?
　　　{?
　　　　Console.WriteLine("SocketException: {0}", e);?
　　　}?
　　　Console.ReadLine();?
　　}?
　}?
}?
//server端?
using System;?
using System.Text;?
using System.IO;?
using System.Net;?
using System.Net.Sockets;?
namespace Project1?
{?
　class Class2?
　{?
　　static void Main()?
　　{?
　　　try?
　　　{?
　　　　int port = 2000;?
　　　　string host = "127.0.0.1";?
　　　　IPAddress ip = IPAddress.Parse(host);?
　　　　IPEndPoint ipe = new IPEndPoint(ip, port);?
　　　　Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);?
　　　　s.Bind(ipe);?
　　　　s.Listen(0);?
　　　　Socket temp = s.Accept();?
　　　　string recvStr = "";?
　　　　byte[] recvBytes = new byte[1024];?
　　　　int bytes;?
　　　　bytes = temp.Receive(recvBytes, recvBytes.Length, 0);?
　　　　recvStr += Encoding.ASCII.GetString(recvBytes, 0, bytes);?
　　　　Console.WriteLine(recvStr);?
　　　　string sendStr = "Ok!Sucess!";?
　　　　byte[] bs = Encoding.ASCII.GetBytes(sendStr);?
　　　　temp.Send(bs, bs.Length, 0);?
　　　　temp.Shutdown(SocketShutdown.Both);?
　　　　temp.Close();?
　　　　s.Shutdown(SocketShutdown.Both);?
　　　　s.Close();?
　　　}?
　　　catch (ArgumentNullException e)?
　　　{?
　　　　Console.WriteLine("ArgumentNullException: {0}", e);?
　　　}?
　　　catch (SocketException e)?
　　　{?
　　　　Console.WriteLine("SocketException: {0}", e);?
　　　}?
　　　Console.ReadLine();?
　　}?
　}?
}?
　　以上程序在VS Express 2005 .Net2.0環境下測試通過。

C#UDP的多路廣播組的發送和接收?
下列范例使用 UdpClient，在通訊端口11000傳送UDP 資料包至多點傳送位址群組 224.268.100.2。它傳送命令列上指定的信息字串。??
C# code?
using System;??
using System.Net;??
using System.Net.Sockets;??
using System.Text;??
public class UDPMulticastSender {??
private static IPAddress GroupAddress =??
IPAddress.Parse("224.168.100.2");??
private static int GroupPort = 11000;??
private static void Send( String message) {??
UdpClient sender = new UdpClient();??
IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort);??
try {??
Console.WriteLine("Sending datagram : {0}", message);??
byte[] bytes = Encoding.ASCII.GetBytes(message);??
sender.Send(bytes, bytes.Length, groupEP);??
sender.Close();??
} catch (Exception e) {??
Console.WriteLine(e.ToString());??
}??
}??
public static int Main(String[] args) {??
Send(args[0]);??
return 0;??
}??
}??

下列范例使用 UdpClient，在通訊端口? 11000? 監聽廣播到多點傳送位址群組 224.168.100.2 的 UDP? 資料包。它接收信息字串，并將信息寫入主控臺 (Console)。??

C# code

using System;??

using System.Net;??

using System.Net.Sockets;??

using System.Text;??

public class UDPMulticastListener {??

private static readonly IPAddress GroupAddress =??

IPAddress.Parse("224.168.100.2");??

private const int GroupPort = 11000;??

private static void StartListener() {??

bool done = false;??

UdpClient listener = new UdpClient();??

IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort);??

try {??

listener.JoinMulticastGroup(GroupAddress);??

listener.Connect(groupEP);??

while (!done) {??

Console.WriteLine("Waiting for broadcast");??

byte[] bytes = listener.Receive( ref groupEP);??

Console.WriteLine("Received broadcast from {0} :/n {1}/n",??

groupEP.ToString(),??

Encoding.ASCII.GetString(bytes,0,bytes.Length));??

}??

listener.Close();??

} catch (Exception e) {??

Console.WriteLine(e.ToString());??

}??

public static int Main(String[] args) {??

StartListener();??

return 0;??

}??

}

using System;??

using System.Net;??

using System.Net.Sockets;??

using System.Text;??

public class UDPMulticastSender {??

private static IPAddress GroupAddress =??

IPAddress.Parse("224.168.100.2");??

private static int GroupPort = 11000;??

private static void Send( String message) {??

UdpClient sender = new UdpClient();??

IPEndPoint groupEP = new IPEndPoint(GroupAddress,GroupPort);??

try {??

Console.WriteLine("Sending datagram : {0}", message);??

byte[] bytes = Encoding.ASCII.GetBytes(message);??

sender.Send(bytes, bytes.Length, groupEP);??

sender.Close();??

} catch (Exception e) {??

Console.WriteLine(e.ToString());??

}??

public static int Main(String[] args) {??

Send(args[0]);??

return 0;??

}??

}

C# code

try

??????????????? {

??????????????????? UdpClient udp=new UdpClient(new IPEndPoint(ipAddress,startPort+i));

??????????????????? udp.Close();????????????????????

??????????????????? unUsedPort=startPort+i;

??????????????????? break;

??????????????? }

??????????????? catch

??????????????? {

??????????????? }

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

using System.Collections;

using System.Collections.Specialized;

using System.Threading;

using System.Net.Sockets;

using System.Net;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

using System.IO;

namespace 聊天工具服務器

{

??? public partial class FormMain : Form

??? {

??????? public FormMain()

??????? {

??????????? InitializeComponent();

??????? }

??????? #region 字段定義

??????? /// <summary>

??????? /// 服務器程序使用的端口，默認為8888

??????? /// </summary>

??????? private int _port = 8888;

??????? /// <summary>

??????? /// 接收數據緩沖區大小2K

??????? /// </summary>

??????? private const int _maxPacket =2 * 1024;

??????? /// <summary>

??????? /// 服務器端的監聽器

??????? /// </summary>

??????? private TcpListener _tcpl = null;

??????? Thread _receiveThread;

??????? /// <summary>

??????? /// 保存所有客戶端會話的哈希表

??????? /// </summary>

??????? private Hashtable _transmit_tb = new Hashtable();

??????? /// <summary>

??????? /// 當前文件路徑

??????? /// </summary>

??????? string MyPath = null;

??????? /// <summary>

??????? /// 用戶基本信息表，包括UserName，UserPwd，UserNich，UserImg，ZX，UserIp

??????? /// </summary>

??????? DataTable TabUser = new DataTable();

??????? /// <summary>

??????? /// 用戶消息表，保存用戶不在線時的消息

??????? /// </summary>

??????? DataTable TabUserMessage = new DataTable();

??????? #endregion

??????? /// <summary>

??????? /// 序列化在線列表，向客戶端返回序列化后的字節數組

??????? /// </summary>

??????? /// <returns>序列化后的字節數組 </returns>

??????? private byte[] SerializeOnlineList()

??????? {

??????????? StringCollection onlineList = new StringCollection();

??????????? foreach (object o in _transmit_tb.Keys)

??????????? {

??????????????? onlineList.Add(o as string);

??????????? }

??????????? IFormatter format = new BinaryFormatter();

??????????? MemoryStream stream = new MemoryStream();

??????????? format.Serialize(stream, onlineList);

??????????? byte[] ret = stream.ToArray();

??????????? stream.Close();

??????????? return ret;

??????? }

??????? /// <summary>

??????? /// 序列化好友列表，向客戶端返回序列化后的datatable

??????? /// </summary>

??????? /// <returns>序列化后的字節數組 </returns>

??????? private bool SerializeFriendList(object obj, Socket clientSkt)

??????? {

??????????? DataTable TabmyFriend = new DataTable();

??????????? TabmyFriend.TableName = obj as string;

??????????? try {

??????????????? TabmyFriend.ReadXml(MyPath + "//UserFriend//" + TabmyFriend.TableName + ".xml");

??????????????? TabmyFriend.Columns.Add("UserImg", typeof(String));

??????????????? TabmyFriend.Columns.Add("UserNich", typeof(String));

??????????????? TabmyFriend.Columns.Add("ZX", typeof(Boolean));

??????????????? TabmyFriend.Columns.Add("UserIp", typeof(String));

??????????????? foreach (DataRow myrow in TabmyFriend.Rows)

??????????????? {

??????????????????? DataRow[] DataRows = TabUser.Select(" UserName = '" + myrow["UserName"].ToString() + "'");

??????????????????? if (DataRows.Length > 0)

??????????????????? {

??????????????????????? myrow["UserImg"] = DataRows[0]["UserImg"].ToString();

??????????????????????? myrow["UserNich"] = DataRows[0]["UserNich"].ToString();

????????????????????? try

????????????????????? {

??????????????????????????? myrow["ZX"] = (bool)DataRows[0]["ZX"];

??????????????????????????? myrow["UserIp"] = DataRows[0]["UserIp"].ToString();

????????????????????? }???

????????????????????? catch

??????????????????????? {

??????????????????????????? myrow["ZX"] = false;

??????????????????????????? myrow["UserIp"] = "";

??????????????????????? }

??????????????????? }

??????????????? }

??????????? }

??????????? catch

??????????? {

??????????????? TabmyFriend.Columns.Add("UserName", typeof(String));

??????????????? TabmyFriend.Columns.Add("UserImg", typeof(String));

??????????????? TabmyFriend.Columns.Add("ZX", typeof(Boolean));

??????????????? TabmyFriend.Columns.Add("UserIp", typeof(String));

??????????? }

??????????? IFormatter format = new BinaryFormatter();

??????????? MemoryStream stream = new MemoryStream();

??????????? format.Serialize(stream, TabmyFriend);

??????????? stream.Position = 0;

??????????? byte[] ret = new byte[_maxPacket];

??????????? int count = 0;

??????????? count = stream.Read(ret, 0, _maxPacket);

??????????? //先發送響應信號，用戶客戶機的判斷

??????????? clientSkt.Send(Encoding.Unicode.GetBytes("cmd::RequestFriendList"));

??????????? while (count >0)

??????????? {

??????????????? clientSkt.Send(ret);

??????????????? count =? stream.Read(ret, 0, _maxPacket);

????????????? }

??????????? //發送結束信號

????????????? clientSkt.Send(Encoding.Unicode.GetBytes("Find::RequestFriendListEnd"));??

????????????? stream.Close();

??????????? return true ;

??????? }

??????? private void FormMain_Load(object sender, EventArgs e)

??????? {

??????????? MyPath = Application.StartupPath;

??????????? Read_User();

??????????? ReadTabUserMessage();

??????????? _receiveThread = new Thread(new ThreadStart(StartUp));

??????????? _receiveThread.Start();

??????? }

??????? /// <summary>

??????? /// 讀取所有用戶信息

??????? /// </summary>

??????? private void Read_User()

??????? {

??????????? try

??????????? {

??????????????? TabUser.ReadXml(MyPath + "//User.xml");

??????????? }

??????????? catch

??????????? {

??????????????? TabUser.TableName = "User";

??????????????? TabUser.Columns.Add("UserName", typeof(String));

??????????????? TabUser.Columns.Add("UserPwd", typeof(String));

??????????????? TabUser.Columns.Add("UserNich", typeof(String));

??????????????? TabUser.Columns.Add("UserImg", typeof(String));

??????????? }

??????????? TabUser.Columns.Add("ZX", typeof(Boolean));

??????????? TabUser.Columns.Add("UserIp", typeof(String));

??????? }

??????? /// <summary>

??????? /// 新用戶上/下線后，更新其好友的（好友列表）

??????? /// </summary>

??????? /// <param name="UserName"> </param>

??????? /// <param name="OnLine"> </param>

??????? /// <param name="IpAddress"> </param>

??????? private void UpdateFriendList(string UserName, bool OnLine, string IpAddress)

??????? {

??????????? DataTable TabmyFriend = new DataTable();

??????????? TabmyFriend.TableName = UserName;

??????????? string svrlog = null;

??????????? string []UserInformation = new string[2];//UserName + "$" + IpAddress;

??????????? UserInformation[0] = UserName;

??????????? UserInformation[1] = IpAddress;

??????????? IFormatter format = new BinaryFormatter();

??????????? MemoryStream stream = new MemoryStream();

??????????? format.Serialize(stream, UserInformation);

??????????? byte[] ret = stream.ToArray();

??????????? stream.Close();

??????????? if (OnLine)

??????????? {

??????????????? svrlog = "cmd::RequestAddFriendList";

??????????? }

??????????? else

??????????? {

??????????????? svrlog = "cmd::RequestRemoveFriendList";

??????????????? DataRow[] DataRows = TabUser.Select(" UserName = '" + UserName + "'");

??????????????? if (DataRows.Length > 0)

??????????????? {

??????????????????? DataRows[0]["ZX"] = false;

??????????????????? DataRows[0]["UserIp"] = "";

??????????????? }

??????????? }

??????????? try

??????????? {

??????????????? TabmyFriend.ReadXml(MyPath + "//UserFriend//" + TabmyFriend.TableName + ".xml");

??????????????? foreach (DataRow myrow in TabmyFriend.Rows)

??????????????? {

??????????????????? if(_transmit_tb.ContainsKey(myrow["UserName"].ToString()))

??????????????????? {

??????????????????????? Socket _clientSkt = _transmit_tb[myrow["UserName"].ToString()] as Socket;

????????????????????? _clientSkt.Send(Encoding.Unicode.GetBytes(svrlog));

????????????????????? _clientSkt.Send(ret);

??????????????????? }

??????????????? }

??????????? }

??????????? catch

??????????? { }

??????? }

[code=C#][/code /// <summary>

??????? /// 線程執行體,轉發消息

??????? /// </summary>

??????? /// <param name="obj">傳遞給線程執行體的用戶名，用以與用戶通信 </param>

??????? private void ThreadFunc(object obj)

??????? {

??????????? //通過轉發表得到當前用戶套接字

??????????? Socket clientSkt = _transmit_tb[obj] as Socket;

????????? //主循環

??????????? while (true)

??????????? {

??????????????? try

??????????????? {

??????????????????? //接受第一個數據包。

??????????????????? //由于程序邏輯結構簡單，所以在這里對客戶機發送的第一個包內容作逐一判斷，

??????????????????? //這里的實現不夠優雅，但不失為此簡單模型的一個解決之道。

??????????????????? byte[] packetBuff = new byte[_maxPacket];

??????????????????? clientSkt.Receive(packetBuff);

??????????????????? string _str = Encoding.Unicode.GetString(packetBuff).TrimEnd('/0');

??????????????????? //如果是發給不在線好友的信息

??????????????????? if (_str.StartsWith("cmd::FriendMessage"))

??????????????????? {

??????????????????????? string UserName = _str.Substring("cmd::FriendMessage".Length, 20).Trim();

??????????????????????? string MessageS = _str.Substring("cmd::FriendMessage".Length + 20, _str.Length - "cmd::FriendMessage".Length - 20);

??????????????????????? SaveMessage(obj as string, UserName, MessageS);

??????????????????????? continue;

??????????????????? }

??????????????????? //如果是離線請求

??????????????????? if (_str.StartsWith("cmd::RequestLogout"))

??????????????????? {

??????????????????????? _transmit_tb.Remove(obj);

??????????????????????? UpdateFriendList((string)obj, false, "");

????????????????????? //? string svrlog = string.Format("[系統消息]用戶 {0} 在 {1} 已斷開... 當前在線人數: {2}/r/n/r/n", obj, DateTime.Now, _transmit_tb.Count);

????????????????????? //? Console.WriteLine(svrlog);

??????????????????????? //向所有客戶機發送系統消息

??????????????????????? //foreach (DictionaryEntry de in _transmit_tb)

??????????????????????? //{

??????????????????????? //??? string _clientName = de.Key as string;

??????????????????????? //??? Socket _clientSkt = de.Value as Socket;

??????????????????????? //??? _clientSkt.Send(Encoding.Unicode.GetBytes(svrlog));

??????????????????????? //}

??????????????????????? Thread.CurrentThread.Abort();

??????????????????? }

??????????????????? //如果是請求好友列表

??????????????????? if (_str.StartsWith("cmd::RequestFriendList"))

??????????????????? {

??????????????????????? SerializeFriendList(obj, clientSkt);?????????????????????

??????????????????????? // 將該用戶不在線時的信息發送給用戶

??????????????????????? DataTable TabMessage = ReadMessage(obj as string);

??????????????????????? if (TabMessage != null)

??????????????????????? {

??????????????????????????? foreach (DataRow myrow in TabMessage.Rows)

??????????????????????????? {

??????????????????????????????? if (myrow["SendUserName"].ToString() == "System::Message")

??????????????????????????????? {

??????????????????????????????????? clientSkt.Send(Encoding.Unicode.GetBytes(myrow["Message"].ToString()));

??????????????????????????????? }

??????????????????????????????? else

??????????????????????????????? {

??????????????????????????????????? clientSkt.Send(Encoding.Unicode.GetBytes("cmd::FriendMessage" + myrow["SendUserName"].ToString().PadRight(20, ' ') + myrow["Message"].ToString()));

??????????????????????????????? }

??????????????????????????? }

??????????????????????? }

??????????????????????? //這里不需要再繼續接受后繼數據包了，跳出當前循環體。

??????????????????????? continue;

??????????????????? }

??????????????????? 如果是請求好友列表

??????????????????? //if (_str.StartsWith("cmd::RequestOnLineList"))

??????????????????? //{

??????????????????? //??? byte[] onlineBuff = SerializeOnlineList();

??????????????????? //??? //先發送響應信號，用戶客戶機的判斷

??????????????????? //??? clientSkt.Send(Encoding.Unicode.GetBytes("cmd::RequestOnLineList"));

??????????????????? //??? clientSkt.Send(onlineBuff);

??????????????????? //??? //這里不需要再繼續接受后繼數據包了，跳出當前循環體。

??????????????????? //??? continue;

??????????????????? //}

??????????????????? //查找用戶

??????????????????? if (_str.StartsWith("Find::FindFriend"))

??????????????????? {

??????????????????????? DataTable TabFind = TabUser.Clone();

??????????????????????? DataRow [] FindRow =null? ;

??????????????????????? string UserName = _str.Substring("Find::FindFriend".Length, _str.Length - "Find::FindFriend".Length);

??????????????????????? if (UserName.Equals("Find::WhoOnLine"))

??????????????????????? { //看誰在線

??????????????????????????? FindRow = TabUser.Select(" ZX = 1");

??????????????????????? }

??????????????????????? else//精確查找

??????????????????????? {

??????????????????????????? FindRow = TabUser.Select("UserName = '" + UserName + "'");

??????????????????????? }

??????????????????????? foreach (DataRow myrow in FindRow)

??????????????????????? {

??????????????????????????? TabFind.ImportRow(myrow);

??????????????????????? }

??????????????????????? clientSkt.Send(Encoding.Unicode.GetBytes("Find::FindFriend"));

??????????????????????? IFormatter format = new BinaryFormatter();

??????????????????????? MemoryStream stream = new MemoryStream();

??????????????????????? format.Serialize(stream, TabFind);

??????????????????????? stream.Position = 0;

??????????????????????? byte[] ret = new byte[_maxPacket];

??????????????????????? int count = 0;

??????????????????????? count = stream.Read(ret, 0, _maxPacket);

??????????????????????? while (count >0)

??????????????????????? {

??????????????????????????? clientSkt.Send(ret);

????????????????????????? count =? stream.Read(ret, 0, _maxPacket);

??????????????????????? }

??????????????????????? clientSkt.Send(Encoding.Unicode.GetBytes("Find::FindFriendEnd"));??

??????????????????????? stream.Close();

??????????????????????? TabFind = null;

??????????????????????? FindRow = null;

//這里不需要再繼續接受后繼數據包了，跳出當前循環體。

??????????????????????? continue;

??????????????????? }

??????????????????? //請求添加好友

??????????????????? if (_str.StartsWith("Find::AddFriendAsk"))

??????????????????? {

??????????????????????? string UserName = _str.Substring("Find::AddFriendAsk".Length, _str.Length - "Find::AddFriendAsk".Length);

??????????????????????? //通過轉發表查找接收方的套接字

??????????????????????? if (_transmit_tb.Count != 0 && _transmit_tb.ContainsKey(UserName))

??????????????????????? {

??????????????????????????? Socket receiverSkt = _transmit_tb[UserName] as Socket;

??????????????????????????? receiverSkt.Send(Encoding.Unicode.GetBytes("Find::AddFriendAsk" + obj as string));

??????????????????????? }

??????????????????????? //這里不需要再繼續接受后繼數據包了，跳出當前循環體。

??????????????????????? continue;

??????????????????? }

??????????????????? //回復答應添加好友

??????????????????? if (_str.StartsWith("Find::AddFriendYes"))

??????????????????? {

??????????????????????? string UserName = _str.Substring("Find::AddFriendYes".Length, _str.Length - "Find::AddFriendYes".Length);

????????????????????? 保存數據

??????????????????????? DataTable TabmyFriend = new DataTable() ;

??????????????????????? //保存該用戶

??????????????????????? TabmyFriend.ReadXml(MyPath + "//UserFriend//" +? obj as string + ".xml");

??????????????????????? DataRow newRow = TabmyFriend.NewRow();

??????????????????????? newRow["UserName"] = UserName;

??????????????????????? TabmyFriend.Rows.Add(newRow);

??????????????????????? TabmyFriend.WriteXml(MyPath + "//UserFriend//" + obj as string + ".xml", XmlWriteMode.WriteSchema, false);

??????????????????????? //保存其好友

??????????????????????? TabmyFriend = new DataTable();

??????????????????????? TabmyFriend.ReadXml(MyPath + "//UserFriend//" + UserName + ".xml");

??????????????????????? DataRow newRow1 = TabmyFriend.NewRow();

??????????????????????? newRow1["UserName"] = obj as string;

??????????????????????? TabmyFriend.Rows.Add(newRow1);

??????????????????????? TabmyFriend.WriteXml(MyPath + "//UserFriend//" + UserName + ".xml", XmlWriteMode.WriteSchema, false);

??????????????????????? TabmyFriend = null;

????????????? //更新好友列表

??????????????????????? SerializeFriendList(obj, clientSkt);

上面發了服務器端,沒發客戶端,現在補上!不知道寫的好不好,見笑了

C# code

public partial class Form1 : Form

??? {

??????? private TcpClient client;

??????? private bool isExit = false;

??????? private NetworkStream networkStream;

??????? private EventWaitHandle allDone = new EventWaitHandle(false, EventResetMode.ManualReset);

??????? #region 用于一個線程操作另一個線程的控件

??????? private delegate void SetListBoxCallback(string str);

??????? private SetListBoxCallback setListBoxCallBack;

??????? private delegate void SetRichTextBoxCallback(string str);

??????? private SetRichTextBoxCallback setRichTextBoxCallBack;

??????? #endregion

??????? public Form1()

??????? {

??????????? InitializeComponent();

??????????? listBoxStatus.HorizontalScrollbar = true;

??????????? setListBoxCallBack = new SetListBoxCallback(SetListBox);

??????????? setRichTextBoxCallBack = new SetRichTextBoxCallback(SetReceiveText);

??????? }

??????? //狀態顯示

??????? private void SetListBox(string str)

??????? {

??????????? listBoxStatus.Items.Add(str);

??????????? listBoxStatus.SelectedIndex = listBoxStatus.Items.Count - 1;

??????????? listBoxStatus.ClearSelected();

??????? }

??????? //接收客戶端信息

??????? private void SetReceiveText(string str)

??????? {

??????????? richTextBoxReceive.AppendText(str);

??????? }

??????? //連接服務器....

??????? private void buttonConnet_Click(object sender, EventArgs e)

??????? {

??????????? client = new TcpClient(AddressFamily.InterNetwork);

??????????? //得到服務器IP

??????????? IPAddress ip= IPAddress.Parse("127.0.0.1");

??????????? //創建一個委托,并知名在異步操作完成時執行的方法

??????????? AsyncCallback callback = new AsyncCallback(RequestCallBack);

??????????? allDone.Reset();

??????????? client.BeginConnect(ip, 7100, RequestCallBack, client);

??????? }

??????? private void RequestCallBack(IAsyncResult ar)

??????? {

??????????? allDone.Set();

??????????? try

??????????? {

??????????????? client = (TcpClient)ar.AsyncState;

??????????????? client.EndConnect(ar);

??????????????? listBoxStatus.Invoke(setListBoxCallBack, string.Format("與服務器{0}連接成功", client.Client.RemoteEndPoint));

??????????????? networkStream = client.GetStream();

??????????????? ReadObject readObject = new ReadObject(networkStream, client.ReceiveBufferSize);

??????????????? networkStream.BeginRead(readObject.bytes, 0, readObject.bytes.Length, ReadCallBack, readObject);

??????????? }

??????????? catch (Exception e1)

??????????? {

??????????????? listBoxStatus.Invoke(setListBoxCallBack, e1.Message);

??????????????? return;

??????????? }

??????? }

??????? //異步操作完成時執行的回調調用的方法

??????? private void ReadCallBack(IAsyncResult ar)

??????? {

??????????? try

??????????? {

??????????????? ReadObject ro = (ReadObject)ar.AsyncState;

??????????????? int count = ro.netStream.EndRead(ar);

??????????????? richTextBoxReceive.Invoke(setRichTextBoxCallBack, System.Text.Encoding.UTF8.GetString(ro.bytes, 0, count));

??????????????? if (isExit == false)

??????????????? {

??????????????????? ro = new ReadObject(networkStream, client.ReceiveBufferSize);

??????????????????? networkStream.BeginRead(ro.bytes, 0, ro.bytes.Length, ReadCallBack, ro);

??????????????? }

??????????? }

??????????? catch (Exception e2)

??????????? {

??????????????? listBoxStatus.Invoke(setListBoxCallBack, e2.Message);

??????????????? return;

??????????? }

??????? }

??????? //發送數據

??????? private void SendString(string str)

??????? {

??????????? try

??????????? {

??????????????? byte[] by = System.Text.Encoding.UTF8.GetBytes(str+"/r/n");

??????????????? networkStream.BeginWrite(by, 0, by.Length, new AsyncCallback(SendCallBack), networkStream);

??????????????? networkStream.Flush();

??????????? }catch(Exception e3){

??????????????? listBoxStatus.Invoke(setListBoxCallBack, e3.Message);

??????????????? return;

??????????? }

??????? }

??????? //發送數據回調的方法

??????? private void SendCallBack(IAsyncResult ar)

??????? {

??????????? try

??????????? {

??????????????? networkStream.EndWrite(ar);

??????????? }

??????????? catch (Exception e4)

??????????? {

??????????????? listBoxStatus.Invoke(setListBoxCallBack, e4.Message);

??????????????? return;

??????????? }

??????? }

??????? private void buttonSend_Click(object sender, EventArgs e)

??????? {

??????????? SendString(richTextBoxSend.Text);

??????????? richTextBoxSend.Clear();

??????? }

??????? private void Form1_FormClosing(object sender, FormClosingEventArgs e)

??????? {

??????????? isExit = true;

??????????? allDone.Set();

??????? }

??? }

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