Problem mit eigener .NET Componente

[Master_BB]

Die Componente

Delphi-Quellcode:

unit ButtonBarU;

interface

uses
  BarButtonsU,
  System.ComponentModel,
  System.Windows.Forms;

const
  WM_Size = 5;

type
  TBarButtonClickEvent = procedure(sender : TButtonItem) of Object;


  TButtonBar = class(Panel)
  strict protected
    procedure WndProc(var AMessage : System.Windows.Forms.Message);             override;
  protected
    FButtons          : TButtonList;
    FOnBarButtonClick : TBarButtonClickEvent;
  protected
    procedure InitializeObject;
  public
    constructor Create;

    property Buttons : TButtonList read FButtons;
  published
    [Category('Buttons'), Description('Raised while a button was clicked')]
    property OnBarButtonClick : TBarButtonClickEvent read FOnBarButtonClick write FOnBarButtonClick;
  end;

implementation

uses
  System.Security.Permissions;

{$REGION TButtonBar}

{ TButtonBar }

constructor TButtonBar.Create;
begin
  inherited;
  InitializeObject;

  FButtons := TButtonList.Create(Self);
end;

procedure TButtonBar.InitializeObject;
begin
  FButtons          := nil;
  FOnBarButtonClick := nil;
end;

{$ENDREGION}

//[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name='FullTrust')]
procedure TButtonBar.WndProc(var AMessage : System.Windows.Forms.Message);
begin
  if AMessage.Msg = WM_SIZE then
    MessageBox.Show(Width.ToString);
    
  Inherited WndProc(AMessage);
end;

end.

ein teil der ButtonsListe

Delphi-Quellcode:

  TButtonList = class(ArrayList)
  protected
    function get_ButtonsWidth  : Int32;


function TButtonList.get_ButtonsWidth: Int32;
begin
  if (FParent <> nil) then
    Result := FParent.Width - (2 * FButtonConst.ButtonSpaceLeftRight)
  else
    Result := 0;
end;

FParent ist die Control und wird beim erstellen der Buttonliste
gefillt also vor dem ersten aufruf von get ButtonsWidth