利用Socket.Send发送信息、Socket.SendFile传输文件

// Displays sending with a connected socket
// using the overload that takes a buffer.
public static int SendReceiveTest1(Socket server)
{
    byte[] msg = Encoding.UTF8.GetBytes("This is a test");
    byte[] bytes = new byte[256];
    try 
    {
        // Blocks until send returns.
        int i = server.Send(msg);
        Console.WriteLine("Sent {0} bytes.", i);

        // Get reply from the server.
        i = server.Receive(bytes);
        Console.WriteLine(Encoding.UTF8.GetString(bytes));
    }
    catch (SocketException e)
    {
        Console.WriteLine("{0} Error code: {1}.", e.Message, e.ErrorCode);
        return (e.ErrorCode);
    }
    return 0;
}

// Establish the local endpoint for the socket.
IPHostEntry ipHost = Dns.GetHostEntry(Dns.GetHostName());
IPAddress  ipAddr = ipHost.AddressList[0];
IPEndPoint ipEndPoint = new IPEndPoint(ipAddr, 11000);

// Create a TCP socket.
Socket client = new Socket(AddressFamily.InterNetwork,
        SocketType.Stream, ProtocolType.Tcp);

// Connect the socket to the remote endpoint.
client.Connect(ipEndPoint);

// There is a text file test.txt located in the root directory.
string fileName = "C:\\test.txt";

// Send file fileName to remote device
Console.WriteLine("Sending {0} to the host.", fileName);
client.SendFile(fileName);

// Release the socket.
client.Shutdown(SocketShutdown.Both);
client.Close();