[置顶]C#中Socket服务端代码分享

最近在对项目中Socket通讯中的服务端代码进行优化，保证能接受尽可能多的客户端的连接，并且不会丢掉连接，不会掉数据包。经过一段时间的反复测试和修改，终于达到了这一要求。服务端代码采用了异步通讯的方式，并使用ManualResetEvent来对线程进行控制。在程序中，ManualResetEvent 的使用很关键。 ManualResetEvent 允许线程通过发信号互相通信。通常，此通信涉及一个线程在其他线程进行之前必须完成的任务。当一个线程开始一个活动（此活动必须完成后，其他线程才能开始）时，它调用
Reset 以将 ManualResetEvent 置于非终止状态，此线程可被视为控制 ManualResetEvent。调用 ManualResetEvent 上的 WaitOne 的线程将阻止，并等待信号。当控制线程完成活动时，它调用 Set 以发出等待线程可以继续进行的信号。并释放所有等待线程。一旦它被终止，ManualResetEvent 将保持终止状态（即对 WaitOne 的调用的线程将立即返回，并不阻塞），直到它被手动重置。可以通过将布尔值传递给构造函数来控制 ManualResetEvent
的初始状态，如果初始状态处于终止状态，为 true；否则为 false。现在贴出主要的代码，欢迎大家指正，代码如下所示：

void ButtonStartListenClick(object sender, System.EventArgs e)

{

try

{

// Check the port value

if(textBoxPort.Text == "")

{

MessageBox.Show("Please enter a Port Number");

return;

}

if (txtConnectNum.Text.Trim() != "")

{

iConnectNum = int.Parse(txtConnectNum.Text.Trim());

Flage = 0;

}

else

{

MessageBox.Show("Please enter a Connect Number");

return;

}

string portStr = textBoxPort.Text;

int port = System.Convert.ToInt32(portStr);

// Create the listening socket...

m_mainSocket = new Socket(AddressFamily.InterNetwork,

SocketType.Stream,

ProtocolType.Tcp);

IPEndPoint ipLocal = new IPEndPoint (IPAddress.Any, port);

// Bind to local IP Address...

m_mainSocket.Bind( ipLocal );

// Start listening...

m_mainSocket.Listen(10000);

// Set the event to nonsignaled state.设置无信号状态的事件

allDone.Reset();

// Create the call back for any client connections...

m_mainSocket.BeginAccept(new AsyncCallback (OnClientConnect), null);

// Wait until a connection is made before continuing.等待连接创建后继续

allDone.WaitOne();

UpdateControls(true);

}

catch(SocketException se)

{

MessageBox.Show ( se.Message );

}

}

// This is the call back function, which will be invoked when a client is connected

public void OnClientConnect(IAsyncResult asyn)

{

try

{

//让它继续处理并建立与客户端的连接

allDone.Set();

// Here we complete/end the BeginAccept() asynchronous call

// by calling EndAccept() - which returns the reference to

// a new Socket object

Socket workerSocket = m_mainSocket.EndAccept (asyn);

// Now increment the client count for this client

// in a thread safe manner

Interlocked.Increment(ref m_clientCount);

if (m_clientCount == 1)

{

lock (this)

{

stopwatch.Start();

dtStart = DateTime.Now;

writeLog("Server Start Socket Connect Time"+dtStart.ToString("yyyy-MM-dd HH:mm:ss fff"));

}

}

// Add the workerSocket reference to our ArrayList

m_workerSocketList.Add(workerSocket);

// Send a welcome message to client

string msg = "Welcome client " + m_clientCount + "\n";

SendMsgToClient(msg, m_clientCount);

// Update the list box showing the list of clients (thread safe call)

UpdateClientListControl();

// Let the worker Socket do the further processing for the

// just connected client

WaitForData(workerSocket, m_clientCount);

// Since the main Socket is now free, it can go back and wait for

// other clients who are attempting to connect

m_mainSocket.BeginAccept(new AsyncCallback ( OnClientConnect ),null);

// Wait until a connection is made before continuing.等待连接创建后继续

allDone.WaitOne();

}

catch(ObjectDisposedException)

{

System.Diagnostics.Debugger.Log(0,"1","\n OnClientConnection: Socket has been closed\n");

}

catch(SocketException se)

{

MessageBox.Show ( se.Message );

}

}

public class SocketPacket

{

// Constructor which takes a Socket and a client number

public SocketPacket(System.Net.Sockets.Socket socket, int clientNumber)

{

m_currentSocket = socket;

m_clientNumber = clientNumber;

}

public System.Net.Sockets.Socket m_currentSocket;

public int m_clientNumber;

// Buffer to store the data sent by the client

public byte[] dataBuffer = new byte[1024];

}

// Start waiting for data from the client

public void WaitForData(System.Net.Sockets.Socket soc, int clientNumber)

{

try

{

if ( pfnWorkerCallBack == null )

{

// Specify the call back function which is to be

// invoked when there is any write activity by the

// connected client

pfnWorkerCallBack = new AsyncCallback (OnDataReceived);

}

SocketPacket theSocPkt = new SocketPacket (soc, clientNumber);

//receiveDone.Reset();

soc.BeginReceive (theSocPkt.dataBuffer, 0,

theSocPkt.dataBuffer.Length,

SocketFlags.None,

pfnWorkerCallBack,

theSocPkt);

//receiveDone.WaitOne();

}

catch(SocketException se)

{

MessageBox.Show (se.Message );

}

}

// This the call back function which will be invoked when the socket

// detects any client writing of data on the stream

public void OnDataReceived(IAsyncResult asyn)

{

SocketPacket socketData = (SocketPacket)asyn.AsyncState ;

try

{

// Complete the BeginReceive() asynchronous call by EndReceive() method

// which will return the number of characters written to the stream

// by the client

//receiveDone.Set();

int iRx = socketData.m_currentSocket.EndReceive (asyn);

char[] chars = new char[iRx + 1];

// Extract the characters as a buffer

System.Text.Decoder d = System.Text.Encoding.UTF8.GetDecoder();

int charLen = d.GetChars(socketData.dataBuffer,

0, iRx, chars, 0);

System.String szData = new System.String(chars);

string msg = "" + socketData.m_clientNumber + ":";

AppendToRichEditControl(msg + szData);

//writeFromClientsMsgLog(msg + szData);

// Send back the reply to the client

string replyMsg = "Server Reply:" + szData.ToUpper();

// Convert the reply to byte array

byte[] byData = System.Text.Encoding.ASCII.GetBytes(replyMsg);

Socket workerSocket = (Socket)socketData.m_currentSocket;

workerSocket.Send(byData);

if (m_clientCount == iConnectNum && Flage == 0)

{

Interlocked.Increment(ref Flage);

string msgTime = "Server End Socket Action Time:";

lock(this)

{

stopwatch.Stop();

//lblTime.Text = stopwatch.Elapsed.Seconds.ToString();

int itime = stopwatch.Elapsed.Milliseconds;

//msgTime += stopwatch.Elapsed.Seconds.ToString()+"--"+itime.ToString();

msgTime += DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss fff");

}

writeLog(msgTime);

writeClientConnectionLog();

//UpdateLabelTime(msgTime);

//byData = System.Text.Encoding.ASCII.GetBytes(msgTime);

//workerSocket.Send(byData);

}

// Continue the waiting for data on the Socket

WaitForData(socketData.m_currentSocket, socketData.m_clientNumber );

}

catch (ObjectDisposedException )

{

System.Diagnostics.Debugger.Log(0,"1","\nOnDataReceived: Socket has been closed\n");

}

catch(SocketException se)

{

if(se.ErrorCode == 10054) // Error code for Connection reset by peer

{

string msg = "Client " + socketData.m_clientNumber + " Disconnected" + "\n";

AppendToRichEditControl(msg);

//writeFromClientsMsgLog(msg);

// Remove the reference to the worker socket of the closed client

// so that this object will get garbage collected

m_workerSocketList[socketData.m_clientNumber - 1] = null;

UpdateClientListControl();

}

else

{

MessageBox.Show (se.Message );

}

}

}

void CloseSockets()

{

if(m_mainSocket != null)

{

m_mainSocket.Close();

}

Socket workerSocket = null;

for(int i = 0; i < m_workerSocketList.Count; i++)

{

workerSocket = (Socket)m_workerSocketList[i];

if(workerSocket != null)

{

workerSocket.Close();

workerSocket = null;

}

}

}

void SendMsgToClient(string msg, int clientNumber)

{

// Convert the reply to byte array

byte[] byData = System.Text.Encoding.ASCII.GetBytes(msg);

Socket workerSocket = (Socket)m_workerSocketList[clientNumber - 1];

//workerSocket.Send(byData);

workerSocket.BeginSend(byData, 0, byData.Length, 0,

new AsyncCallback(SendCallback), workerSocket);

}

private void SendCallback(IAsyncResult asyn)

{

Socket client = (Socket)asyn.AsyncState;

// 完成数据发送.

int bytesSent = client.EndSend(asyn);

}

完整的代码可以在我的资源中下载到，资源的名称为C#中Socket服务端通讯的代码。