Can One application be developed in more than one programming language

[AceK]

Hi everyone, I've recently been asked to add new features in a GUI app that was developed using Delphi. The problem is that I don't know Delphi but I know C++ and Qt. So is it possible to develop the new features using C++ and Qt and somehow link them to the existing app or must I know Delphi?

[Duthomhas]

Yes, and it isn't really that difficult, but you are still better off just using Delphi and avoiding many of the hurdles you would otherwise have to jump.

It isn't a difficult language to grasp, and you do many things similarly to how you would do them in C++ or Qt. Basic idioms are different, of course, but google helps with that a lot.

Do you have access to an appropriate Delphi compiler?

[AceK]

Thank you for your reply Duoas. familiarizing myself with Delphi is not a problem but I am more interested in the process of extending a Delphi program with C++ so that in future I don't have to study every programming language out there for future problems like this one.

[Duthomhas]

Don't take this wrong, but you'd be wasting your (and your employer's) time.

Many applications are written in multiple languages. You can link functions in different modules (DLLs or EXEs) into your Delphi program using an external directive.

For example:

type
  HTHEME = THANDLE;

function OpenThemeData( Wnd: HWND; ClassList: PWideChar ): HTHEME; stdcall;
  external 'UxTheme.dll';

If you name your function different than the imported function name, use the name sub-directive.


You can link to object files with the {$L myfile.obj} compiler directive.

The Delphi documentation is pretty complete about these features.

Hope this helps get you started.