Sending a packet in C# via TCP?

Question

I'll try and explain my question below, I have tried googling for an answer but firstly, I don't really know what I should be googling and I haven't found anything that makes sense to me, I was wondering if someone could explain it? Many Thanks.

Hello. I am trying to send a simple network packet using TCP, I have done it using UDP pretty easily as its really easy with UDP, I was wondering if anyone could help me do the equivalent in TCP? I tried using a TcpClient, but it doesn't have a Send method the same as UDP?

public void OnUdp()
{
    var client = new UdpClient(Host, Port);
    client.Send(rubbish, rubbish.Length);
}

Solution

This is the example from https://msdn.microsoft.com/en-us/library/system.net.sockets.tcpclient.aspx

static void Connect(String server, String message) 
{
  try 
  {
    // Create a TcpClient.
    // Note, for this client to work you need to have a TcpServer 
    // connected to the same address as specified by the server, port
    // combination.
    Int32 port = 13000;
    TcpClient client = new TcpClient(server, port);

    // Translate the passed message into ASCII and store it as a Byte array.
    Byte[] data = System.Text.Encoding.ASCII.GetBytes(message);         

    // Get a client stream for reading and writing.
   //  Stream stream = client.GetStream();

    NetworkStream stream = client.GetStream();

    // Send the message to the connected TcpServer. 
    stream.Write(data, 0, data.Length);

    Console.WriteLine("Sent: {0}", message);         

    // Receive the TcpServer.response.

    // Buffer to store the response bytes.
    data = new Byte[256];

    // String to store the response ASCII representation.
    String responseData = String.Empty;

    // Read the first batch of the TcpServer response bytes.
    Int32 bytes = stream.Read(data, 0, data.Length);
    responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
    Console.WriteLine("Received: {0}", responseData);         

    // Close everything.
    stream.Close();         
    client.Close();         
  } 
  catch (ArgumentNullException e) 
  {
    Console.WriteLine("ArgumentNullException: {0}", e);
  } 
  catch (SocketException e) 
  {
    Console.WriteLine("SocketException: {0}", e);
  }

  Console.WriteLine("\n Press Enter to continue...");
  Console.Read();
}

Comments

[spodger]

Try reading the TcpClient documentation. It has an example. msdn.microsoft.com/en-us/library/…

[Umair M]

Have a read on this one too

[jdweng]

See the msdn examples. The example uses TCP with the socket class. You can replace the Socket Class with any Class that inherits the socket like TCPListener and TCPClient : docs.microsoft.com/en-us/dotnet/framework/network-programmin‌​g/…

[spender]

TCP provides a connection oriented communication over an underlying packet oriented datagram network. The concept of "sending" a TCP "packet" is miguided.

[Tom Blodget]

Agreeing with @spender, see this comparison. With TCP, you send a stream of bytes. The receiver gets none or some at a time and has to buffer until it can process an actionable sequence of bytes. The trivial case, when each byte is individually actionable, is rare.

[jdweng]

This is a very bad example. It closes the connection after one message. For beginners it will cause a lot of grief.

[Tom Blodget]

It also assumes that the message has only characters that are also in the ASCII character set, without any parameter validation. That makes it too easy to silently corrupt the data.