Question

Delphi 7 :: Custom Component - "Control '' has no parent window"

Asked by: Marius0188

Hi Experts,

I have derived an new component from TCustomCombobox and has overriden the Create method.
Something I believe is wrong with the way I override this method because when placing the newly created component on a form in designtime I receive the following error:
Control '' has no parent window.

Please see the override method:

constructor TComboboxDateFilter.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
 
  Self.Style := csDropDownList;
  Self.Items.Add('All Rows');
  Self.Items.Add('7 Days');
  Self.Items.Add('30 Days');
  Self.Items.Add('60 Days');
  Self.Items.Add('90 Days');
  Self.Items.Add('120 Days');
  Self.Items.Add('1 Year');
  Self.ItemIndex := 0;
end;

                                  
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Asked On
2008-05-07 at 02:09:26ID23382066
Topics

Delphi Components

,

Delphi IDE

Participating Experts
1
Points
500
Comments
2

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Answers

 

by: ciulyPosted on 2008-05-07 at 02:45:24ID: 21514624

changing the style implies recreating the window. so jsut to be on the safe side, though an ugly workaround, try this:

  inherited Create(AOwner);

  parent:=TWinControl(AOwner);// insert this line

  Self.Style := csDropDownList;

and btw, you don't need to call self. in the constructor. there is no ambiguity there :)

 

by: Marius0188Posted on 2008-05-07 at 02:59:45ID: 21514720

Thanks.
Seems to work.

20120131-EE-VQP-002

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