C＃-服务器/ C ++客户端：Socket.Accept（）永远不会完成

Question

I'm writing a simple C++ client that should connect to a C# server. And, while the client runs throught fine and even states it sent a bunch of bites, the C# server never gets past listener.Acceppt() :

Console.WriteLine("Waiting for a connection...");
// Program is suspended while waiting for an incoming connection.
Socket handler = listener.Accept();

I took the server source from here: Microsoft MSDN: Synchronous Server Socket Example

The client code I use can be found here: Microsoft MSDN: Complete Winsock Client Code

I also checked to server with the according C# client , which worked fine. I also checked the return values of the client, which also looked pretty plausible. So I'd guess the problem lies somewhere in how C++ / C# handle the details.

I tried Wireshark to find some hints, but mysteriously there was absolutely no trace of any communication on the used port (11000).

Where should I start looking to solve this issue?

Update: All communication at the moment runs just locally. I tried my IPAddress (from ipconfig ) and 127.0.0.1 for both server and client.

I just have one network adapter installed, I use that IP adress. The client checks the getaddrinfo(argv[1], DEFAULT_PORT, &hints, &result) and returns valid information (eg TCP as protocol). connect() returns 0 , which should be ok.

Update 2: I tried different combinations of C++/C# Server-Client-Setups:

• C++-Server, C++ Client: Works
• C++-Server, C# Client: Works
• C#-Server, C# Client: Works
• C#-Server, C++ Client: Does not work
• C#-Server, putty : Works

Update 3: I tried Wireshark on the other Server-Client constellations, but neither of them did show any traffic on tcp.port == 11000 , although they did work (see Update 2). It looks like Wireshark does not show any results, because everything is just local (see Wireshark localhost traffic capture )

Answer 1

I had the same problem. The connection with winsock is asynchronous. And the example in C# that you are using is synchronous. You have to use a Asynchronous example to get communication with your C++ code.

I used this two examples!

C Sharp server https://msdn.microsoft.com/en-us/library/fx6588te(v=vs.110).aspx

C plus plus client https://msdn.microsoft.com/en-us/library/windows/desktop/ms737591(v=vs.85).aspx