Why the composite component fails to parent controls?
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Published on 2010-04-19T18:49:14Z
Indexed on
2010/04/20
10:03 UTC
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delphi
Hi,
I created my own Component : TPage , which Contains Subcomponent TPaper (TPanel). The problem is, that when I put controls such as TMemo or TButton on the TPaper (which fills up nearly whole area), the controls do not load at all. see example below
TPaper = class(TPanel)
protected
constructor Create(AOwner: TComponent);override;
destructor Destroy;override;
public
procedure Paint; override;
end;
TPage = class(TCustomControl)
private
FPaper:TPaper;
protected
procedure CreateParams(var Params:TCreateParams); override;
public
constructor Create(AOwner: TComponent);override;
destructor Destroy;override;
published
property Paper: TPaper read FPaper write FPaper;
end;
constructor TPage.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
PaperOrientation:=poPortrait;
PaperSize:=psA4;
PaperBrush:=TBrush.Create;
PaperBrush.Color:=clWhite;
PDFDocument:=Nil;
FPaper:=TPaper.Create(Self);
FPaper.Parent:=Self;
FPaper.SetSubComponent(True);
end;
... Memo1 is parented in TPaper (TPanel) at design-time, but after pressing "Run" it does not exist.
procedure TForm1.btn1Click(Sender: TObject);
begin
if not Assigned(Memo1) then ShowMessage('I do not exist'); //Memo1 is nil
end;
Have you any idea what's wrong?
Thanks a lot
P.S Delphi 7
When I put TMemo inside TPaper and save the unit (Unit1), after inspection of associated dfm file, there is no trace of TMemo component. (Thats why it can not load to app.)
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