How can I apply Delphi XE2 skins to forms in a DLL?

Question

Using Delphi XE2, you have the option to embed custom styles (skins) to a VCL project.
Everything works fine. Now I have some forms into a separated dll that I show dynamically.
Of course those are not skinned. How can I rectify that?

I guess I must do some call to TVisualStyle somehow, but no luck.

The host:

procedure TForm1.Button1Click(Sender: TObject); 
var   
  l: THandle;   
  p: procedure (const h: THandle); stdcall; 
begin   
 l:= LoadLibrary('project1.dll');   
 if l > 0 then   
 begin
        @p:= GetProcAddress(l,'ShowIt');
        p(Application.Handle);
        FreeLibrary(l);   
  end; 
end;

The dll:

procedure ShowIt(const h: THandle);stdcall;
var
  form: TForm;
  b: TButton;
  han: THandle;
begin
  han:= Application.Handle;
  Application.Handle:= h;
  form :=Tform.Create(Application);
  b:= TButton.Create(form);
  b.Parent:= form;
  b.Caption:= 'ytes';
  b.Left:= 2;
  b.Top:= 2;
  form.ShowModal;
  form.Release;
  Application.Handle:= han;
end;

exports ShowIt ;
begin
end.

Pretty standard stuff. Now, what exactly must be done to make the dll form use the host's style theme?

Answer 1

You have two distinct instances of the VCL. You have set the style in the StyleServices instance owned by the executable, but your DLL has no knowledge of that. You could solve this by either:

1. Passing the style settings to a function in your DLL that applies those settings to the other StyleServices instance.
2. Use packages so that you only have a single VCL instance.

Answer 2

I had a lot of trouble with this and it was because I was using themes rather than VCL.THEMES and VCL.STYLES .

Delphi was throwing up a customeStyleException saying "style not found" or EcustomStyleException "Feature not supported by this style"