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Creating Visual Components at run time

MrBig
MrBig asked
on
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Last Modified: 2010-04-04
I am designing a component derived from TPanel, I wont to have an image on it (my own image component).

This is the code so far...

unit ImageContainer;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls,U_ImageExtended;

type
  TImageContainer = class(TPanel)
  Procedure SetImage(Value : TImageExtended);
  private
  FImage : TImageExtended;
    { Private declarations }
  protected
    { Protected declarations }
  public
  constructor Create(AOwner: TComponent); override;
    { Public declarations }
  Property Image : TImageExtended Read FImage Write SetImage;
  published

    { Published declarations }
  end;

procedure Register;

implementation


constructor TImageContainer.Create(AOwner: TComponent);
Begin
    Inherited Create(AOwner);
end;

Procedure TImageContainer.SetImage(Value : TImageExtended);
Begin
     FImage := Value;
end;

procedure Register;
begin
  RegisterComponents('My Components', [TImageContainer]);
end;

end.

When I try to put this on a form and execute any methods related to the Image I get a 'Read of address 'FFFFFF' message. The image is obviously not correctly created.
How can I create it?

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Commented:
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Hi,

First, i dont know what TImageExtended is...

You need to create a TImage in your constructor - like this :

Type
  TImageExtended = TImage;

FImage : TImageExtended;
...
constructor TImageContainer.Create(AOwner: TComponent);
Begin
 Inherited Create(AOwner);
 FImage:=TImageExtended.create(self);
end;

I also hink you should use Assign :

Procedure TImageContainer.SetImage(Value : TImageExtended);
Begin
 FImage.Assign := Value;
end;

I have not tried this sample, but i think this is how you should write it.

Good luck
Peter
Hmm, Sorry Aleq,
You where there first, but i did not see your comment.
Peter :-)
Hi MrBig,

Well I tried to compile your code, but you use your own TImageExtended, so I can't help you so much.

Anyway I think that you could use:
constructor TImageContainer.Create(AOwner: TComponent);
Begin
  Inherited Create(AOwner);
  FImage := TImageExtended.Create;
{or, depending you TImageExtended}
  FImage := TImageExtended.Create(AOwner);
end;

and put the line:
  Property Image : TImageExtended Read FImage Write SetImage;

after then published section of the class

PeterLarsen changed the proposed answer to a comment

Author

Commented:
Hey u all, thanks for the quick answers, you all did a good job at it but Aleq beat you to the points, it's all yours aleq, and thax again!!
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