C#利用服務器實現客戶端之間通訊

這兩天在學習C#，C#高級編程真的是厚厚的一本書QAQ。

昨天看了一下里面的通訊部分(其實還沒怎麼看),看了網上一些人的博客，本身在他們的博客基礎上寫了一個通訊。

先來說述下我本身對於整個Socket通訊過程的理解，畢竟初學，說錯見諒，知道錯了會改正~

首先在服務端新建一個serverSocket，對其進行初始化（通常包含AddressFamily:IP地址類型，SocketType:Socket傳輸數據方式，ProtoType:傳輸協議）;

接着咱們要設置server端要綁定的IP:port;而後開始監聽，並設置最多同時監聽多少個Client.

 

這時，服務端就在等待狀態，直到某一個Client鏈接到這個ip:port上，這時serverSocket.Accept()工做，得到這個鏈接。（此時的鏈接是有地址信息的哦！記得保存）

得到鏈接以後，server就能夠和這個Client進行通訊了,當加入第二個Client（咱們稱其爲ClientB）時，Server接收到ClientB的消息，能夠將這個消息轉發給前一個Client（咱們稱其爲ClientA），當受到ClientA的消息，也能夠轉發給ClientB。這樣就實現了Clients之間的通訊了。（重點在保存鏈接信息！！）

 

那麼如今貼上代碼講解：

Server端代碼

  1 namespace SocketServer
  2 {
  3     class Program
  4     {
  5         private static byte[] result = new byte[1024];
  6       
  7         static Socket serverSocket;
  8         private static string client;
  9         private static Socket clientSocket;
 10         //我這裏存了兩個Client，由於本身電腦開了兩個Client，不會有多的
 11         //理論上應該開一個Socket[]來保存信息，最好用一個二元組將client的信息和鏈接綁定起來
 12         //這樣就能夠實現斷開鏈接後下次登錄仍是能夠識別是這個Client
 13         private static Socket clientSocketA=null;
 14         private static Socket clientSocketB=null;
 15         
 16         static void Main(string[] args)
 17         {
 18             Program.SetPort(8885);
 19         }
 20         private static void SetPort(int port)
 21         {
 22             IPAddress ip = IPAddress.Parse("127.0.0.1");//set ip
 23             serverSocket = new Socket(AddressFamily.InterNetwork,
 24                 SocketType.Stream, ProtocolType.Tcp);//initialize
 25             serverSocket.Bind(new IPEndPoint(ip, port));//bind
 26             serverSocket.Listen(10);
 27             //進入監聽狀態
 28             Console.WriteLine("監聽{0}成功", serverSocket.LocalEndPoint.ToString());
 29             //開啓一個線程來監聽客戶端鏈接
 30             Thread myThread = new Thread(ListenClientConnect);
 31             myThread.Start();
 32             Console.ReadLine();
 33 
 34         }
 35         /// <summary>
 36         /// 監聽客戶端鏈接
 37         /// </summary>
 38         private static void ListenClientConnect()
 39         {
 40             while (true)
 41             {
 42                 //Client鏈接上後 獲得這個鏈接
 43                 clientSocket = serverSocket.Accept();
 44 
 45                 //這裏我由於只有兩個Client，因此就簡單寫了
 46                 if (clientSocketA == null)
 47                 {
 48                     clientSocketA = clientSocket;
 49                 }
 50                 else if (clientSocketB == null)
 51                 {
 52                     clientSocketB = clientSocket;
 53                 }
 54                 else
 55                 {
 56                     //當其中一個斷開了，又從新鏈接時，須要再次保存鏈接
 57                     if (clientSocketB.IsBound)
 58                     {
 59                         clientSocketA = clientSocketB;
 60                         clientSocketB = clientSocket;
 61                     }
 62                     else
 63                     {
 64                         clientSocketB = clientSocketA;
 65                         clientSocketA = clientSocket;
 66                     }
 67                     
 68                 }
 69                 clientSocket.Send(Encoding.ASCII.GetBytes("say hello"));
 70                 //開個線程接收Client信息
 71                 Thread receivedThread = new Thread(ReceiveMessage);
 72                 receivedThread.Start(clientSocket);
 73 
 74             }
 75         }
 76      
 77         private static void ReceiveMessage(object clientSocket)
 78         {
 79             Socket myClientSocket = (Socket) clientSocket;
 80             
 81             while (true)
 82             {
 83                 try
 84                 {
 85                     int revceiveNumber = myClientSocket.Receive(result);
 86                     //Console.WriteLine("接受客戶端{0}消息{1}", myClientSocket.RemoteEndPoint.ToString()
 87                     //    , Encoding.ASCII.GetString(result, 0, revceiveNumber));
 88                     Console.WriteLine(Encoding.ASCII.GetString(result, 0, revceiveNumber));
 89                     if (myClientSocket == clientSocketA)
 90                     {
 91                         Console.WriteLine("receive from A");
 92                         if (clientSocketB!=null&&clientSocketB.IsBound)
 93                         {
 94                             Console.WriteLine("a IS BOUND");
 95                             clientSocketB.Send(result, 0, revceiveNumber, SocketFlags.None);
 96                         }
 97                         else
 98                         {
 99                             myClientSocket.Send(Encoding.ASCII.GetBytes("the people is not online! Send Failed!"));
100                             Console.WriteLine("對方不在線上，發送失敗！");
101                         }
102                     }
103                     else
104                     {
105                         Console.WriteLine("receive from B");
106                         if (clientSocketA != null && clientSocketA.IsBound)
107                         {
108                             Console.WriteLine("a IS BOUND");
109                             clientSocketA.Send(result, 0, revceiveNumber, SocketFlags.None);
110                         }   
111                         else
112                         {
113                             myClientSocket.Send(Encoding.ASCII.GetBytes("the people is not online! Send Failed!"));
114                             Console.WriteLine("對方不在線上，發送失敗！");
115                         }
116 
117                     }
118                     
119                 }
120                 catch(Exception ex)
121                 {
122                     Console.WriteLine(ex.Message);
123                     myClientSocket.Shutdown(SocketShutdown.Both);
124                     myClientSocket.Close();
125                     break;
126 
127                 }
128             }
129 
130         }
131     }
132 }

Client端代碼(由於都差很少 就只貼一個了)

 1 namespace SocketClient
 2 {
 3     class Program
 4     {
 5         private static byte[] result = new byte[1024];
 6         private static Socket clientSocket;
 7         private static void ListenServer()
 8         {
 9             while (true)
10             {
11                 result = new byte[1024];
12                 int receiveLength = clientSocket.Receive(result);
13                 
14                 Console.WriteLine("{0}", Encoding.ASCII.GetString(result, 0, receiveLength));
15             }
16            
17         }
18         static void Main(string[] args)
19         {
20 
21             IPAddress ip = IPAddress.Parse("127.0.0.1");
22             clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
23             try
24             {
25                 clientSocket.Connect(ip, 8885);
26                 Console.WriteLine("鏈接成功！");
27 
28             }
29             catch (Exception e)
30             {
31                 Console.WriteLine("鏈接失敗！");
32                 return;
33             }
34             Thread threadRead = new Thread(ListenServer);
35             threadRead.Start();
36            
37 
38             while(true)
39             {
40                 try
41                 {
42                     Thread.Sleep(1000);
43                     string sendMessage = Console.ReadLine();
44                     clientSocket.Send(Encoding.ASCII.GetBytes("Sylvia:"+sendMessage));
45                     
46                 }
47                 catch (Exception ex)
48                 {
49                     clientSocket.Shutdown(SocketShutdown.Both);
50                     clientSocket.Close();
51                     break;
52                 }
53 
54             }
55             Console.WriteLine("發送完畢 按回車退出");
56             Console.ReadKey();
57         }
58     }
59 }

 

寫的時候要特別注意一下Send信息的時候，注意byte[]的傳輸大小，很容易變成byte[]數組的大小而不是內容的大小。

這個你們就本身嘗試吧