Simple Network Programming in C# for Beginners?

Question

I am currently new to C# and I need to understand simple server-client architecture!

I am currently trying to write a simple server/client program where basically a client can send a variable to a server and the server can send it to another client. Problem is that I am really blind to this as I am still very new to C# although I have some experience with Java (But still not with networking).

My question is:

1. How many files will i Have to write?
2. Can anybody be nice enough to provide me with a framework or example for a program like this?
3. What is a TCP server?

This is intended to be for an online game. One client will roll the dice and the server must show all the other clients that this is the value the first client rolled.

Any help would be greatly appreciated!

Answer 1

Answer to all of your questions: MSDN - Network Programming (.NET 4)

Answer 2

Since you are planning on TCP (because you want state) you need to develop a strategy. You'll get plenty of information about establishing a connection and moving some sort of data back and forth. Google will give you more than you can handle. Without doing all the work, here are a few steps to get you oriented.

1) Connection Registration - When a client comes online and wants to communicate with the server it first needs to say "Hey I'm here and want to role some dice." This initial handshake could be a connection id that is used for a heart beat and/or transactions. The server will use this to identify data and the respective thread if open.

2) Heart Beat - Now that the client has registered with the server the client is responsible for providing a heart beat saying it's still there and still planning to continue work. Typically every 3 - 10 seconds is good.

3) Develop the Request/Response protocol - For "every command" there will be a formal process. This formal process will include the connection id but also a request id. The client will not accept a response unless it receives the corresponding request id. Furthermore, every request will require a success or fail response to identify if it conforms to the API or what not. Within the request will be the command or action to perform. Some people use int's to dispatch a command id then use a switch on the id to call an entry-point method (cmd id = 1 is connect(), cmd id = 2 is rolldice(), etc). You might include additional payload that identifies the result from the command.

In short, 1 is the handshake, 2 is the keep-alive and 3 is passing data back and forth.

Now whether to use socket or WCF, I'd recommend to have a basic understanding of TcpClient programming then run with WCF. You'll be amazed how simple socket programming is but the overhead is a killer. Nothing to be intimidated by. It's a lot of work to coordinate calls, threads and not to mention security. WCF on the other hand does shave some of this overhead off.

I'd check out this question...

How to use socket based client with WCF (net.tcp) service?