Problem mit Nachricht aus DLL

[neolithos]

In der Anwendung:

Delphi-Quellcode:

  TMouseHookMsg = packed record
    dwMsg,
    dwMouseMsg : Cardinal;
    pt : TSmallPoint;
  end;

Delphi-Quellcode:

  TForm1 = ....
    procedure WMMouseNotify(var Message : TMouseHookMsg); message WM_APP + 11;
....

Delphi-Quellcode:

procedure TfrmMain.WMMouseNotify(var Message: TMouseHookMsg);
begin
  with Message do
    Label4.Caption := Format('x: %d y: %d', [pt.x, pt.y]);
end;

Delphi-Quellcode:

constructor TForm1.Create(fOwner: TComponent);
begin
  inherited;
  RegisterMouseHook(Handle, WM_APP + 11);
end;

destructor TForm1.Destroy;
begin
  UnRegisterMouseHook;
  inherited;
end;