AppCentral implements communication between DLL libraries and host applications using interfaces. It supports Delphi and C#. At the moment host applications can only be written in Delphi, plugins / libraries in Delphi or C#.

This project is my fourth implementation of this idea. First I implemented it for myself, then for two companies, and now I have written it again from scratch to publish it. So far this is the best implementation.

You find a short usage info here: how-to short info

This project was written using Delphi 11 Community Edition and Visual Studio 2022 Community Edition. I used x86 only and .NET 4.8 for the demo, but meanwhile I tested other .NET versions as well. Be sure to have a look into the how-to file, because there are a few possible pitfalls.

Register an interface in Delphi

type
  IAppDialogs = interface
  ['{EA3B37D8-5603-42A9-AC5D-5AC9C70E165C}']
    procedure ShowMessage(const AMessage: WideString); safecall;
  end;

  TAppDialogs = class(TInterfacedObject, IAppDialogs)
   public
     procedure ShowMessage(const AMessage: WideString); safecall;
   end;

implementation

{ TAppDialogs }

procedure TAppDialogs.ShowMessage(const AMessage: WideString);
begin
  Vcl.Dialogs.ShowMessage(AMessage);
end;

initialization
  TAppCentral.Reg<IAppDialogs>(TAppDialogs.Create);

finalization
  TAppCentral.Unreg<IAppDialogs>;

Fetch this interface inside the host application or in a DLL

TAppCentral.Get<IAppDialogs>.ShowMessage('This is a message!');

Or using C#

if (AppCentral.TryGet<IAppDialogs>(out IAppDialogs Dialogs))
{
  Dialogs.ShowMessage("Message from DLL: C# DLL registered!");
}

I would like to support more .NET versions and I would like to (done) support C# as a host application. So I plan to implement the full functionality in C# as well.

Other languages are on the list as well.

MPL 1.1/GPL 2.0/LGPL 2.1, see LICENSE.md

You can send your commits as pull requests. This is the easiest way for you since I'll do the merging if neccessary.

You can contact me as user jaenicke at https://en.delphipraxis.net/ or by mail: [email protected]

Feel free to write, if you have any comments, feedback or the like.