Question

Simple task:
I would like to make a program (parent.exe). There are three buttons. When I click Button1, Form1 appears; when Button 2, Form2 appears; when Button3, Form3 appears…

Form1, Form2, Form3 are stored in three different dlls (Form1dll.dll, Form2dll.dll, Form3dll.dll).

I wanted to make parent program (parent.exe) run modular. I planned to add and remove dlls, but Parent.exe requires all dlls to be present, otherwise an exception occures.

How can I solve the problem?

Thanx

Here is code from parent.exe:

  procedure ShowForm1;stdcall;external 'Project1dll.dll' name 'ShowForm1';
  procedure ShowForm2;stdcall;external 'Project2.dll' name 'ShowForm2';
  procedure ShowForm3;stdcall;external 'Project3.dll' name 'ShowForm3';

var
  ParentForm: TParentForm;

implementation

{$R *.DFM}



procedure TParentForm.Button1Click(Sender: TObject);
begin
  ShowForm1;
end;

procedure TParentForm.Button2Click(Sender: TObject);
begin
  ShowForm2;
end;

procedure TParentForm.Button3Click(Sender: TObject);
begin
  ShowForm3;
end;

Answer 1

The way you’ve got it set up, the program looks for the DLLs at load time. What you need is to set the DLLs up as plugins. Take a look at the JVPlugin framework in the JVCL. It has exactly what you’re looking for.