Hi there,

I want to develop a C# plugin for a Delphi application that I use but do not
know too much about interop.  I think it should be possible but I am just
not sure where to start.  Can someone give me points on where I can find the
information I need to get started?

The plug-in initialization process is as follows:

1.    During startup of the Delphi application, the application scans all
DLLs residing in the /plugins directory.
2.    If a DLL in this directory exposes a method with a given signature,
the method is called to initialize the plugin.
      An example Delphi signature would be as follows:

           function IdentifyPlugIn (ID: Integer): PChar

Sound straightforward.  I have to deal with the following as well:

3.    Certain methods are tied to the application's even model and will be
called when certain events occur.  An
       example would be:

           procedure OnCreate ()

4.    I can register one or more callback methods with the application.
This is the business logic of the app.  The method used to register the
callbacks would look something as follows:

           Var
               IDE_MenuState:  procedure (ID, Index:  Integer;  Enabled:
Bool); cdecl;
               IDE_Connected:  function:  Bool;  cdecl;
               IDE_GetConnectionInfo:  procedure (var Username, Password,
Database:  PChar);  cdecl;
               IDE_GetBrowserInfo:  procedure (var ObjectType, ObjectOwner,
ObjectName:  PChar);  cdecl;

           procedure RegisterCallback (Index: Integer; Addr: Pointer);
cdecl;
           begin
               case Index of
                   10:  @IDE_MenuState := Addr;
                   11:  @IDE_Connected := Addr;
                   12:  @IDE_GetConnectionInfo := Addr;
                   13:  @IDE_GetBrowserInfo := Addr;
           end;

If anyone could direct me to the appropriate docs that will guide me through
the implementation of this I would be grateful.

Cheers,
Darryl