TcpClient does not get disconnected? - C# Discussion Boards

Re: Async TcpListener recieves ClientAccept after stoping listening. How to notify it that the client disconnected?

31-Oct-09 20:06

That is great of adding additional messages with TcpClient/TcpListener classes. It sounds wierd to add specific messages to be processed by them to indicate they are due to close OMG | :OMG:

In any case, I close the connection from client to server and from server to client by closing NetworkStream first and then the TcpClient.

tcpClient.GetStream().Close();
tcpClient.Close();

It does not affect them in either way, still producing those ClientAccept message to server

Are there better ways to work with Socket class instead of that Tcp abstraction?

Чесноков

N a v a n e e t h31-Oct-09 21:57

Re: Async TcpListener recieves ClientAccept after stoping listening. How to notify it that the client disconnected? [modified]

31-Oct-09 21:57

It looks like you are new to network programming. I'd suggest to stay away from asynchronous methods for now. Spawn new threads or use ThreadPool to do the work. Once you feel comfortable with that design, try for asynchronous method. Manually creating threads and using it for handling connections and messages works well. You need asynchronous methods only when you need high scalability.

That said, there is no method to stop the asynchronous call especially when the call involves unmanaged code execution. A call to EndAccept will not help as it waits until the operation completes.

Chesnokov Yuriy wrote:
Are there better ways to work with Socket class instead of that Tcp abstraction?

It depends on what you are doing. If you are doing for learning, TcpListener and TcpClient should be enough. For any serious network programming work with Socket class directly. This[^] MSDN article may help you.

Best wishes,
Navaneeth

Chesnokov Yuriy31-Oct-09 23:36

Re: Async TcpListener recieves ClientAccept after stoping listening. How to notify it that the client disconnected?

31-Oct-09 23:36

No. I'm new to C# sockets.
I was coding async sockets in C++ before with winsock. It has windows handle to process all connection/disconnection etc... messages

Internet Traffic Firewall and Sniffer[^]
MFC Telnet Application[^]

C# sockets in async mode are quite different

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modified on Sunday, November 1, 2009 6:51 AM

Chesnokov Yuriy1-Nov-09 0:56

Re: Async TcpListener recieves ClientAccept after stoping listening. How to notify it that the client disconnected?

1-Nov-09 0:56

BTW if no clients have been connected to the TcpListener, that ClientConnect message still happen???

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N a v a n e e t h1-Nov-09 1:32

Re: Async TcpListener recieves ClientAccept after stoping listening. How to notify it that the client disconnected?

1-Nov-09 1:32

Do you mean TcpListenerClientConnectAsyncCallback method will get called if no clients connected? It will not get called when there are no connections.

Best wishes,
Navaneeth

Chesnokov Yuriy1-Nov-09 2:35

TcpClient does not get disconnected?

1-Nov-09 2:35

Yes. After I call Stop() method on TcpListener.

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Chesnokov Yuriy31-Oct-09 10:37

Re: TcpClient does not get disconnected?

31-Oct-09 10:37

How to notify TcpClient that it is disconnected?

1. I start async TcpListener
2. Once the client is connected it reads all data it sent also in async mode
3. Then simply close NetworkStream and close the client connection

private void TcpListenerDataReadAsyncCallback(IAsyncResult ar)
{
TcpClient tc = (TcpClient)ar.AsyncState;
NetworkStream ns = tc.GetStream();

//read all client data

ns.Close();
tc.Close();
}

In the client console, I wait in the loop with small sleeps for a long long while to wait if the server will send somthing, testing tcpClient.Connected property.
But it never becomes false???

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N a v a n e e t h31-Oct-09 18:20

Re: TcpClient does not get disconnected?

31-Oct-09 18:20

Polling is one way to identify the listener status. You have to send a message to server and check the delivery status. If message got delivered successfully, server is connected.

Best wishes,
Navaneeth

Chesnokov Yuriy31-Oct-09 19:59

Re: TcpClient does not get disconnected?

31-Oct-09 19:59

Sending the message will induce the listener to recieve it and process.
In the listener I handle specific messages. It will need to process then connection test message in addition?

Do I need to insert additional sending of some data in that loop? with NetworkStream

//wait 5 secs for data from server
for (int i = 0; i < 10 * 5; i++)
{
if (networkStream.DataAvailable == true)
{
//process recieved data from server
}                                
Thread.Sleep(100);
//???send more data with networkStream???
if (tcpClient.Connected == false)
{
break;
}                                
}

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N a v a n e e t h31-Oct-09 21:45

Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked.

31-Oct-09 21:45

Chesnokov Yuriy wrote:
In the listener I handle specific messages. It will need to process then connection test message in addition?

Yes. It can just process this message and acknowledge back.

Best wishes,
Navaneeth

lexical131-Oct-09 7:47

lexical1

31-Oct-09 7:47

Hi..!!
i add the paint event and both the shapes will be drawn on the form when i
run the progra, just in case if the statement of radio buttons or if() statements are not present. if i write them it don't give any error but only square comes on screen.
if i put this code on form_load then e.graphics is not recognized.what should i do...?????? don't know..plz reply if sumbdy knows...thanxx..

private void Shapes_Paint(object sender, PaintEventArgs e)
{
if (Square.Checked == true)
{
e.Graphics.DrawRectangle(Pens.Blue, 180, 80, 80, 80);
}
if(Triangle.Checked == true)
{
e.Graphics.DrawPolygon(Pens.Red, new Point[] { new
Point(300, 150), new Point(400, 250), new Point(200,250) });
}
}

Re: Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked. [modified]

0x3c031-Oct-09 8:02

0x3c0

31-Oct-09 8:02

Tip: Look at the PRE tags

The e.Graphics field is a Graphics type. To get an instance of this, set the Form's BackgroundImage property to a new Bitmap, passing the Form's ClientHeight and ClientWidth parameters. Then use your normal DrawXXX methods on the result returned from Graphics.FromImage(YourForm.BackgroundImage)

OSDev

modified on Sunday, November 1, 2009 3:39 AM

Re: Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked.

Richard MacCutchan31-Oct-09 10:47

Richard MacCutchan

31-Oct-09 10:47

0x3c0 wrote:
Tip 2: Use plain English

That's a bit rude. The poster is obviously someone whose first language is not English, but has still tried hard to make their question clear.

Re: Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked.

0x3c031-Oct-09 21:40

0x3c0

31-Oct-09 21:40

I was a touch cranky last night to be honest. I'm not too happy with the way that sounds, and I agree it was rude. Edited

OSDev

Re: Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked.

Richard MacCutchan31-Oct-09 21:53

Richard MacCutchan

31-Oct-09 21:53

It's a trap we can all fall into quite easily - I'm as guilty as anyone. I make it a rule now always to use the preview button on my replies and read through a couple of times before I post. And then I re-read it after posting just in case.

The good thing about these forums is that not only do we police the spammers, but also each other. Smile | :)

Re: Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked.

Luc Pattyn31-Oct-09 8:17

Luc Pattyn

31-Oct-09 8:17

Hi,

you are right, all painting should be done in the Paint handler.

however if your drawing isn't to be constant, you should call Invalidate() when a change is needed.
So here, add CheckedChanged handlers to your checkboxes and have them call Invalidate; you may even share such a handler for many Controls.

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

Re: Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked.

lexical131-Oct-09 19:37

lexical1

31-Oct-09 19:37

thanx..i got it and iots working now..

Re: Drawing/Graphics in C#: Draw shapes like rectangle & triangle when respective radio button is checked.

Luc Pattyn1-Nov-09 0:26

Luc Pattyn

1-Nov-09 0:26

you're welcome.

Smile | :)

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

question

anooshe31-Oct-09 7:45

anooshe

31-Oct-09 7:45

iwant to write CSMA/CD with c#

not a

Luc Pattyn31-Oct-09 8:14

Luc Pattyn

31-Oct-09 8:14

Luc Pattyn

I only read code that is properly indented, and rendered in a non-proportional font; hint: use PRE tags in forum messages

dan!sh 31-Oct-09 9:34

dan!sh

31-Oct-09 9:34

No need to ask. Go ahead, please.

It's not necessary to be so stupid, either, but people manage it. - Christian Graus, 2009 AD

Pete O'Hanlon31-Oct-09 9:54

Pete O'Hanlon

31-Oct-09 9:54

Gosh - it's been a long time since anybody mentioned Carrier Sense Multiple Access with Collision Detection. Good on you. What's your question?

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.

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Richard MacCutchan31-Oct-09 10:49

Richard MacCutchan

31-Oct-09 10:49

anooshe wrote:
iwant to write CSMA/CD with c#

For what purpose?