MDI-Form & MDI-Child & DLL's

[Remko]

This works for me:
The DLL (.dpr):

Delphi-Quellcode:

library MyDLL;

uses
  SysUtils,
  Classes,
  Windows,
  Forms,
  uMDIChild in 'uMDIChild.pas' {MDIChild}; // This is the unit that contains the mdi child form

var PrevApplication: TApplication;
  PrevScreen: TScreen;

procedure DLLEntryProc(EntryCode: integer);
begin
  case EntryCode of
    DLL_PROCESS_ATTACH:
    begin
      // Do Initialization stuff here.  Called when a process loads the DLL
      PrevApplication := Application;
      PrevScreen := Screen;
    end;
    DLL_PROCESS_DETACH:
    begin
      // Do Finalization stuff here.  Called when a process unloads the DLL
      Application := PrevApplication;
      Screen := PrevScreen;
    end;
  end;
end;

procedure CreateForm(A: TApplication; S: TScreen); export;
begin
  Application := A;
  Screen := S;
  TMDIChild.Create(Application);
end;

exports CreateForm;

begin
  DLLProc := @DLLEntryProc;
  DLLEntryProc(DLL_PROCESS_ATTACH);
end.

In your mainform declare like this:

Delphi-Quellcode:

procedure CreateForm(A: TApplication; S: TScreen); external 'MyDLL.dll';

And create an MDI child like this:

Delphi-Quellcode:

CreateForm(Application, Screen);

The clientform has a constructor:

Delphi-Quellcode:

constructor TMDIChild.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
end;