如何为 Windows Phone 创建和使用 TCP 套接字客户端应用程序【msdn】

1.连接到 TCP 套接字服务器

使用 System.Net.Sockets API 创建一个套接字并连接到服务器。为了清楚起见，System.Net.Sockets API 的调用被封装在 SocketClient 类中。

定义头（使用 _socket 变量存储 Socket 对象。_clientDone 变量是一个 ManualResetEvent，用于协调通过Sockets API 调用的异步调用）：

// Cached Socket object that will be used by each call for the lifetime of this class
Socket _socket = null;

// Signaling object used to notify when an asynchronous operation is completed
static ManualResetEvent _clientDone = new ManualResetEvent(false);

// Define a timeout in milliseconds for each asynchronous call. If a response is not received within this
// timeout period, the call is aborted.
const int TIMEOUT_MILLISECONDS = 5000;

// The maximum size of the data buffer to use with the asynchronous socket methods
const int MAX_BUFFER_SIZE = 2048;

在 SocketClient.cs 中，添加以下方法，该方法将创建 TCP 套接字，并向服务器发送异步连接请求。此操作的响应将由内联回调进行处理

public string Connect(string hostName, int portNumber)
{
string result = string.Empty;

DnsEndPoint hostEntry = new DnsEndPoint(hostName, portNumber);

_socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

// Create a SocketAsyncEventArgs object to be used in the connection request
SocketAsyncEventArgs socketEventArg = new SocketAsyncEventArgs();
socketEventArg.RemoteEndPoint = hostEntry;

socketEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(delegate(object s, SocketAsyncEventArgs e)
{
result = e.SocketError.ToString();

_clientDone.Set();
});

_clientDone.Reset();

_socket.ConnectAsync(socketEventArg);

_clientDone.WaitOne(TIMEOUT_MILLISECONDS);

return result;
}

2.向 TCP 套接字服务器发送数据

public string Send(string data)
{
string response = "Operation Timeout";

// We are re-using the _socket object that was initialized in the Connect method
if (_socket != null)
{
// Create SocketAsyncEventArgs context object
SocketAsyncEventArgs socketEventArg = new SocketAsyncEventArgs();

// Set properties on context object
socketEventArg.RemoteEndPoint = _socket.RemoteEndPoint;
socketEventArg.UserToken = null;

// Inline event handler for the Completed event.
// Note: This event handler was implemented inline in order to make this method self-contained.
socketEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(delegate(object s, SocketAsyncEventArgs e)
{
response = e.SocketError.ToString();

// Unblock the UI thread
_clientDone.Set();
});

// Add the data to be sent into the buffer
byte[] payload = Encoding.UTF8.GetBytes(data);
socketEventArg.SetBuffer(payload, 0, payload.Length);

// Sets the state of the event to nonsignaled, causing threads to block
_clientDone.Reset();

// Make an asynchronous Send request over the socket
_socket.SendAsync(socketEventArg);

// Block the UI thread for a maximum of TIMEOUT_MILLISECONDS milliseconds.
// If no response comes back within this time then proceed
_clientDone.WaitOne(TIMEOUT_MILLISECONDS);
}
else
{
response = "Socket is not initialized";
}

return response;
}

3.接收来自 TCP 套接字服务器的数据

public string Receive()
{
string response = "Operation Timeout";

// We are receiving over an established socket connection
if (_socket != null)
{
// Create SocketAsyncEventArgs context object
SocketAsyncEventArgs socketEventArg = new SocketAsyncEventArgs();
socketEventArg.RemoteEndPoint = _socket.RemoteEndPoint;

// Setup the buffer to receive the data
socketEventArg.SetBuffer(new Byte[MAX_BUFFER_SIZE], 0, MAX_BUFFER_SIZE);

// Inline event handler for the Completed event.
// Note: This even handler was implemented inline in order to make this method self-contained.
socketEventArg.Completed += new EventHandler<SocketAsyncEventArgs>(delegate(object s, SocketAsyncEventArgs e)
{
if (e.SocketError == SocketError.Success)
{
// Retrieve the data from the buffer
response = Encoding.UTF8.GetString(e.Buffer, e.Offset, e.BytesTransferred);
response = response.Trim('\0');
}
else
{
response = e.SocketError.ToString();
}

_clientDone.Set();
});

// Sets the state of the event to nonsignaled, causing threads to block
_clientDone.Reset();

// Make an asynchronous Receive request over the socket
_socket.ReceiveAsync(socketEventArg);

// Block the UI thread for a maximum of TIMEOUT_MILLISECONDS milliseconds.
// If no response comes back within this time then proceed
_clientDone.WaitOne(TIMEOUT_MILLISECONDS);
}
else
{
response = "Socket is not initialized";
}

return response;
}

/// <summary>
/// Closes the Socket connection and releases all associated resources
/// </summary>
public void Close()
{
if (_socket != null)
{
_socket.Close();
}
}