论坛 › 帖子回收 › 面向连接的Socket编程(基础篇)

尐譫灬ゝ 发表于 2008-9-2 17:50:45

面向连接的Socket编程(基础篇)

对于TCP的Socket编程，主要分二部分：
      一、服务端Socket侦听：
      服务端Socket侦听主要分以下几个步骤，按照以下几个步骤我们可以很方便的建立起一个Socket侦听服务，来侦听尝试连接到该服务器的客户Socket，从而建立起连接进行相关通讯。
      1、创建IPEndPoint实例，用于Socket侦听时绑定
         

1http://www.cnblogs.com/Images/OutliningIndicators/None.gifIPEndPoint ipep =
new IPEndPoint(IPAddress.Any, 6001);

      2、创建套接字实例

1http://www.cnblogs.com/Images/OutliningIndicators/None.gif//创建一个套接字
2http://www.cnblogs.com/Images/OutliningIndicators/None.gif            serverSocket =
new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
  
      这里创建的时候用ProtocolType.Tcp，表示建立一个面向连接(TCP)的Socket。

      3、将所创建的套接字与IPEndPoint绑定


1http://www.cnblogs.com/Images/OutliningIndicators/None.gif
//将所创建的套接字与IPEndPoint绑定
2http://www.cnblogs.com/Images/OutliningIndicators/None.gif            serverSocket.Bind(ipep);

      4、设置套接字为收听模式
  
1http://www.cnblogs.com/Images/OutliningIndicators/None.gif//设置套接字为收听模式
2http://www.cnblogs.com/Images/OutliningIndicators/None.gif            serverSocket.Listen(10);

      以上这四步，我们已经建立了Socket的侦听模式，下面我们就来设置怎么样来获取客户Socket连接的实例，以及连接后的信息发送。

      5、在套接字上接收接入的连接
   
1http://www.cnblogs.com/Images/OutliningIndicators/None.gifwhile (true)
2http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif            http://www.cnblogs.com/Images/dot.gif{
3http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                try
4http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif                http://www.cnblogs.com/Images/dot.gif{
5http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    //在套接字上接收接入的连接
6http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    clientSocket = serverSocket.Accept();
7http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    clientThread =
new Thread(new ThreadStart(ReceiveData));
8http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    clientThread.Start();
9http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif                }
10http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                catch (Exception ex)
11http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif                http://www.cnblogs.com/Images/dot.gif{
12http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    MessageBox.Show("listening Error: "
+ ex.Message);
13http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif                }
14http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif            }

      通过serverSocket.Accept()来接收客户Socket的连接请求，在这里用循环可以实现该线程实时侦听，而不是只侦听一次。当程序运行serverSocket.Accept()时，会等待，直到有客户端Socket发起连接请求时，获取该客户Socket，如上面的clientSocket。在这里我用多线程来实现与多个客户端Socket的连接和通信，一旦接收到一个连接后，就新建一个线程，执行ReceiveData功能来实现信息的发送和接收。

      6、 在套接字上接收客户端发送的信息和发送信息

1http://www.cnblogs.com/Images/OutliningIndicators/None.gifprivate
void ReceiveData()
2http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif        http://www.cnblogs.com/Images/dot.gif{
3http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            bool keepalive =
true;
4http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            Socket s = clientSocket;
5http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            Byte[] buffer =
new Byte[1024];
6http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
7http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            //根据收听到的客户端套接字向客户端发送信息
8http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            IPEndPoint clientep = (IPEndPoint)s.RemoteEndPoint;
9http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            lstServer.Items.Add("Client："
+ clientep.Address +
"("+clientep.Port+")");
10http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            string welcome =
"Welcome to my test sever ";
11http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            byte[] data =
new
byte[1024];
12http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            data = Encoding.ASCII.GetBytes(welcome);
13http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            s.Send(data, data.Length, SocketFlags.None);
14http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
15http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            while (keepalive)
16http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif            http://www.cnblogs.com/Images/dot.gif{
17http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                //在套接字上接收客户端发送的信息
18http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
int bufLen =
0;
19http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                try
20http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif                http://www.cnblogs.com/Images/dot.gif{
21http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    bufLen = s.Available;
22http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
23http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    s.Receive(buffer, 0, bufLen, SocketFlags.None);
24http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    if (bufLen ==
0)
25http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                        continue;
26http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif                }
27http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                catch (Exception ex)
28http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif                http://www.cnblogs.com/Images/dot.gif{
29http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    MessageBox.Show("Receive Error:"
+ ex.Message);
30http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    return;
31http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif                }
32http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                clientep = (IPEndPoint)s.RemoteEndPoint;
33http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                string clientcommand = System.Text.Encoding.ASCII.GetString(buffer).Substring(0, bufLen);
34http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
35http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                lstServer.Items.Add(clientcommand +
"("+clientep.Address +
":"+clientep.Port+")");
36http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
37http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif            }
38http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
39http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif        }

      通过IPEndPoint clientep = (IPEndPoint)s.RemoteEndPoint;我们可以获取连接上的远程主机的端口和IP地址，如果想查询该主机的其它属性如主机名等，可用于上一篇讲的Dns.GetHostByAddress(string ipAddress)来返回一个IPHostEntry对象，就可以得到。另外我们要注意的是，通过Socket发送信息，必须要先把发送的信息转化成二进字进行传输，收到信息后也要把收到的二进字信息转化成字符形式，这里可以通过Encoding.ASCII.GetBytes(welcome);和Encoding.ASCII.GetString(buffer).Substring(0, bufLen);来实现。
      以上就是服务端Socket侦听模式的实现，只要有远程客户端Socket连接上后，就可以轻松的发送信息和接收信息了。下面我们来看看客户端Socket是怎么连接上服务器的。

      二、客户端连接

      客户端Socket连接相对来说比较简单了，另外说明一下，在执行客户端连接前，服务端Socket侦听必须先启动，不然会提示服务器拒绝连接的信息。

      1、创建IPEndPoint实例和套接字
1http://www.cnblogs.com/Images/OutliningIndicators/None.gif
//创建一个套接字
2http://www.cnblogs.com/Images/OutliningIndicators/None.gif            IPEndPoint ipep =
new IPEndPoint(IPAddress.Parse("127.0.0.1"), 6001);
3http://www.cnblogs.com/Images/OutliningIndicators/None.gif            clientSocket =
new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

      这个跟服务端Socket侦听差不多，下面一步由服务端Socket的侦听模式变成连接模式。

      2、将套接字连接到远程服务器


1http://www.cnblogs.com/Images/OutliningIndicators/None.gif//将套接字与远程服务器地址相连
2http://www.cnblogs.com/Images/OutliningIndicators/None.gif
try
3http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif            http://www.cnblogs.com/Images/dot.gif{
4http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                clientSocket.Connect(ipep);
5http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif            }
6http://www.cnblogs.com/Images/OutliningIndicators/None.gif            catch (SocketException ex)
7http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif            http://www.cnblogs.com/Images/dot.gif{
8http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                MessageBox.Show("connect error: "
+ ex.Message);
9http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                return;
10http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif            }

      前面已说明，如果在执行Socket连接时，服务器的Socket侦听没有开启的话，会产生一个SocketException异常，如果没有异常发生，那恭喜你，你已经与服务器连接上了，接下来就可以跟服务器通信了。
  
      3、接收信息


1http://www.cnblogs.com/Images/OutliningIndicators/None.gifwhile (true)
2http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif            http://www.cnblogs.com/Images/dot.gif{
3http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                //接收服务器信息
4http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
int bufLen =
0;
5http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                try
6http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif                http://www.cnblogs.com/Images/dot.gif{
7http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    bufLen = clientSocket.Available;
8http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
9http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    clientSocket.Receive(data, 0, bufLen, SocketFlags.None);
10http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    if (bufLen ==
0)
11http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif                    http://www.cnblogs.com/Images/dot.gif{
12http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                        continue;
13http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif                    }
14http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif                }
15http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                catch (Exception ex)
16http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gifhttp://www.cnblogs.com/Images/OutliningIndicators/ContractedSubBlock.gif                http://www.cnblogs.com/Images/dot.gif{
17http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    MessageBox.Show("Receive Error:"
+ ex.Message);
18http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                    return;
19http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif                }
20http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
21http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                string clientcommand = System.Text.Encoding.ASCII.GetString(data).Substring(0, bufLen);
22http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
23http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                lstClient.Items.Add(clientcommand);
24http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
25http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif            }

      4、发送信息


1http://www.cnblogs.com/Images/OutliningIndicators/None.gif//向服务器发送信息
2http://www.cnblogs.com/Images/OutliningIndicators/None.gif
3http://www.cnblogs.com/Images/OutliningIndicators/None.gif            byte[] data =
new
byte[1024];
4http://www.cnblogs.com/Images/OutliningIndicators/None.gif            data = Encoding.ASCII.GetBytes(txtClient.Text);
5http://www.cnblogs.com/Images/OutliningIndicators/None.gif            clientSocket.Send(data, data.Length, SocketFlags.None);

      客户端的发送信息和接收信息跟服务器的接收发送是一样的，只不过一个是侦听模式而另一个是连接模式。

      以下是程序的运行界面，这些在源码下载里都可以看到：

      1、服务端界面：
      http://images.cnblogs.com/cnblogs_com/licongjie/Server1.jpg
      
      2、客户端界面：
      http://images.cnblogs.com/cnblogs_com/licongjie/Client1.jpg

      好了，关于面向连接的Socket就讲到这里了，以实例为主，希望对那些派得上用场的朋友能够看得明白。另外提一下，这里服务端开启侦听服务、客户端连接服务端都采用线程方式来实现，这样服务端能够跟多个客户端同时通信，不用等候，当然还有另外一种方式可以实现那就是异步socket。
源码下载：
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litjerk 发表于 2008-9-8 09:38:26

感谢楼主的无私分享！

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