TCPClient Question

[Frank]

I wonder if anyone could give me a suggestion on how to best handle this
scenario.

I wish to have an aspx page contact a server and receive messages.
Initially, a login messge is sent, then after being validated, a second
message is sent which contains data to complete a stock market trade. The
server then should respond not only once, but with several return messages.

So far all I have found are examples that send, receive, and disconnect,
which I have working. However, since all returning data to the client should
be in response to the order submitted, I cannot simply continue to resend
the original data for the trade. I need to keep the connection open and the
grab all incoming messages until the client quits.

Could anyone suggest how I should modfy the following code to keep the
connection open and continue to rceive subsequent messages?



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.
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();
}

 

[Kevin Spencer]

Just a thought, but it is not necessary to maintain an open connection, if
you are writing both the server and the client. The server could be a Web
Services app. Web Services also support Application and Session State. In
fact, I have worked on an app that has a client-side SWF which makes Web
Service calls to a Web Service periodically, and the Web Service maintains
most of the data on the server side, either in Application or Session State.

If you were to do this, you could simply have a Web Service method that the
client Page could call at intervals to check whether or not data was
available, and receive it if it is.

HTTP is a very reliable protocol, and maintaining an open TCP/IP connection
is going to be problematic.

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
You can lead a fish to a bicycle,
but it takes a very long time,
and the bicycle has to *want* to change.

I wonder if anyone could give me a suggestion on how to best handle this
scenario.

I wish to have an aspx page contact a server and receive messages.
Initially, a login messge is sent, then after being validated, a second
message is sent which contains data to complete a stock market trade. The
server then should respond not only once, but with several return
messages.

So far all I have found are examples that send, receive, and disconnect,
which I have working. However, since all returning data to the client
should be in response to the order submitted, I cannot simply continue to
resend the original data for the trade. I need to keep the connection open
and the grab all incoming messages until the client quits.

Could anyone suggest how I should modfy the following code to keep the
connection open and continue to rceive subsequent messages?



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.
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();
}