How to communicate between a c# and a Delphi application?

Question

I need to interface my application (Delphi+MS SQL Server: D from now on) with another application (c#+SQL Server: C from now on).

C has a minimalistic Windows Forms user interface and the big job it does is connecting to PDAs sending and receiving data from them.

So they idea is that the UI for the C user interface is removed and they just keep the code needed for communication with DB and with PDA.

So I need that C can speak to D and vice versa.

D to C: So somehow on some events (like TButton.OnPress) D will send some data to C. So I need to call methods exposed by C.

C to D: D needs to react to some actions performed by C. So C will call some methods exposed by D. Even if in the first stage D will just "expose a stored procedure".

I never did something like this. What to do? D is currently a single exe (win32).

Which technique do you suggest?

Answer 1

If the user interface in C is going to be removed, then I would recommend to wrap C in a single COM object that you can use transparently from Delphi.

Answer 2

There are a plethora of options. Sockets are probably the most robust, but if both apps run on the same machine you can use window messages (WndProc and friends) or named pipes.