如何为 Windows Phone 创建和使用 UDP 套接字客户端应用程序

/// <summary>
/// Send the given data to the server using the established connection
/// </summary>
/// <param name="serverName">The name of the server</param>
/// <param name="portNumber">The number of the port over which to send the data</param>
/// <param name="data">The data to send to the server</param>
/// <returns>The result of the Send request</returns>
public string Send(string serverName, int portNumber, 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 = new DnsEndPoint(serverName, portNumber);

// 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.SendToAsync(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>
/// Receive data from the server
/// </summary>
/// <param name="portNumber">The port on which to receive data</param>
/// <returns>The data received from the server</returns>
public string Receive(int portNumber)
{
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 = new IPEndPoint(IPAddress.Any, portNumber);

// 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.ReceiveFromAsync(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();
}
}