A simple server question

[Ray Mitchell]

Hello,

I've inherited the following code and am trying to get it
to work. As I understand it's purpose, it creates a
server, listens for a client to connect, does some work
with the client, then loops back around and listens for
the client to reconnect again in case it should become
disconnected. If the client never disconnects it just
sits there waiting forever.

Although the code does seem to work I get the following
errors the first few times through the loop each time
after the client connects, then it settles down and
resumes listening properly. I'm not sure what is going on
since I'm new to this networking business but all-in-all
the way this is implemented seems like a kluge to me. All
suggestions of a better way to do this are welcome.

Thanks,
Ray Mitchell

Output from first iteration:

Starting listener...
Client connected...

Output from next few iterations after client work is done:

Starting listener...
Exception2: Not listening. Please call the Start() method.
Starting listener...
Exception2: Not listening. Please call the Start() method.
Starting listener...
Exception2: Not listening. Please call the Start() method.
Starting listener...
Exception2: Not listening. Please call the Start() method.
....
....
....
Starting listener...
Client connected...
The Code:

using System;
using System.Net;
using System.Net.Sockets;

class Class1
{
[STAThread]
static void Main(string[] args)
{
IPAddress ipAddress = Dns.GetHostByName
("MYHOST").AddressList[0];
TcpListener server = null;

while (true)
{
try
{
try
{
Console.WriteLine("Starting listener...");
server = new TcpListener(ipAddress, 6007);
server.Start();
}
catch (Exception e1)
{
}
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Client connected...");
// Do work with client here...
}
catch (Exception e2)
{
Console.WriteLine("Exception2: " + e2.Message);
}
}
}
}

[Ignacio Machin \( .NET/ C# MVP \)]

HI Ray,

Why do you repeately create and start a new server on each iteration?
I would try this:
class Class1
{
[STAThread]
static void Main(string[] args)
{
IPAddress ipAddress = Dns.GetHostByName
("MYHOST").AddressList[0];
TcpListener server = null;

try
{
Console.WriteLine("Starting listener...");
server = new TcpListener(ipAddress, 6007);
server.Start();
}
catch (Exception e1)
{
}

while (true)
{
try{
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Client connected...");
// Do work with client here...
}
catch (Exception e2)
{
Console.WriteLine("Exception2: " + e2.Message);
}
}
}
} //method
} //class
Cheers,

--
Ignacio Machin,
ignacio.machin AT dot.state.fl.us
Florida Department Of Transportation
"Ray Mitchell" <Ra*****************@MeanOldTeacher.com> wrote in message
news:09****************************@phx.gbl...

Hello,

I've inherited the following code and am trying to get it
to work. As I understand it's purpose, it creates a
server, listens for a client to connect, does some work
with the client, then loops back around and listens for
the client to reconnect again in case it should become
disconnected. If the client never disconnects it just
sits there waiting forever.

Although the code does seem to work I get the following
errors the first few times through the loop each time
after the client connects, then it settles down and
resumes listening properly. I'm not sure what is going on
since I'm new to this networking business but all-in-all
the way this is implemented seems like a kluge to me. All
suggestions of a better way to do this are welcome.

Thanks,
Ray Mitchell

Output from first iteration:

Starting listener...
Client connected...

Output from next few iterations after client work is done:

Starting listener...
Exception2: Not listening. Please call the Start() method.
Starting listener...
Exception2: Not listening. Please call the Start() method.
Starting listener...
Exception2: Not listening. Please call the Start() method.
Starting listener...
Exception2: Not listening. Please call the Start() method.
...
...
...
Starting listener...
Client connected...
The Code:

using System;
using System.Net;
using System.Net.Sockets;

class Class1
{
[STAThread]
static void Main(string[] args)
{
IPAddress ipAddress = Dns.GetHostByName
("MYHOST").AddressList[0];
TcpListener server = null;

while (true)
{
try
{
try
{
Console.WriteLine("Starting listener...");
server = new TcpListener(ipAddress, 6007);
server.Start();
}
catch (Exception e1)
{
}
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Client connected...");
// Do work with client here...
}
catch (Exception e2)
{
Console.WriteLine("Exception2: " + e2.Message);
}
}
}
}