Help with Asynchronous Sockets [OnDataReceived]

or nakash

Hey.
I am new with the Asynchronous sockets and I am trying to make a little program.
I want when the client sends the string "doitall", the server does something, I succeeded to do that with the client but I faild with the server. This is the code:

        public void OnDataReceived(IAsyncResult asyn)
        {
            try
            {
                CSocketPacket theSockId = (CSocketPacket)asyn.AsyncState;
                int byteCount = 0;
                byteCount = theSockId.thisSocket.EndReceive(asyn);
                char[] chars = new char[byteCount + 1];
                Encoding.UTF8.GetDecoder().GetChars(theSockId.dataBuffer, 0, byteCount, chars, 0);
                string str = new string(chars);
                AppendText(str);
                if (str == "doitall")
                {
                    MessageBox.Show("works.");
                }
                WaitForData(m_socWorker);
            }
            catch (SocketException se)
            {
                MessageBox.Show(se.Message);
            }
        }

Whats the problem?
And how to send data to a specific IP address?

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Sam Hobbs16y ago
What you need to do is to study the code and the relevant documentation and learn what is being done. You need to read the article that the sample code is with. If there is not a good article with the sample code, then you need to find something that explains it to you. Sample code without a good article is not good. Sites such as this do have articles that only have sample code without much of an explanation, but that is not good. The authors that provide the sample code don't spend the time to explain things and the reason is because it takes time. You can't expect to get really good explanations of everything from forums such as this.

The only reason I know how to do asynchronous programmeing is because I have read the Microsoft documentation and articles. If you have a more specific question then I will try to help. I really think however that you need to spend some time learning instead of attempting to peice together sample code without understanding how it works.
or nakash16y ago
What do you mean? what do I need to do in order to solve this problem? I copied this code from an article somewhere.

        public void WaitForData(System.Net.Sockets.Socket soc)
        {
            try
            {
                if (pfnWorkerCallBack == null)
                {
                    pfnWorkerCallBack = new AsyncCallback(OnDataReceived);
                }
                CSocketPacket theSocPkt = new CSocketPacket();
                theSocPkt.thisSocket = soc;
                soc.BeginReceive(theSocPkt.dataBuffer, 0, theSocPkt.dataBuffer.Length, SocketFlags.None, pfnWorkerCallBack, theSocPkt);
            }
            catch (SocketException se)
            {
                MessageBox.Show(se.Message);
            }

        }

That is the WaitForData code.
Sam Hobbs16y ago
I don't see where you read the data into theSockId.dataBuffer. If the data is read in WaitForData, then you need to move that up so it is done before you try using theSockId.dataBuffer.