如何使用C＃中的套接字异步回复客户端？

Question

I have basically implemented this asynchronous server socket example (and the corresponding client). Using it, I can respond to the client if I follow the example exactly, ie, if the call to Send() the response is in the ReadCallback() method.

If, however, I try and send a response outside of here, ie, in a callback that I've attached to my message processing routine (running in a different thread), I get this error, saying the Socket is not connected. If I try and send a response somewhere else in the Server code, say in the while(true) loop that's listening to incoming connections, I get the same error.

Am I missing something fundamental here?

Edit:

Ok, so I read Two-way communication in socket programming using C , and I now think , according to that answer, that I have to modify the example I linked to so that I reply to the server on the socket returned by the accept process. My goal is to be able to call Send() outside of the receive callback, say from Main() , after the client and server are connected.

Please can someone suggest how I modify the example to achieve what I want? I'm getting thoroughly confused about this, and don't want to create a separate stream if I don't need to (which according to the question I posted, I don't need to...).

Answer 1

If you want to keep the connection open then would need to persist the handler variable as that is the open socket connection. Then whenever you want to send that connection a message you retrieve its socket and send.

Also, you obviously wouldn't call Shutdown() and Close() on the handler variable.