class(TPersistent) - Zugriff auf "höhere" Prozeduren

[Merlin1988]

1. DANKE an alle die mir geholfen haben
2. Ich hab es jetzt geschafft.

Delphi-Quellcode:

unit TestOwner;

interface

uses
  Windows, Messages, SysUtils, Classes, Controls, ExtCtrls;

type
  TUnter = class(TPersistent)
  private
    FZahl : Integer;
    FOnChange : TNotifyEvent;
    procedure SetZahl(const Value: Integer);
  protected
    procedure Change; virtual;
  published
    property OnChange: TNotifyEvent read FOnChange write FOnChange;
    property Zahl : Integer read FZahl write SetZahl;
  end;

type
  TTestOwner = class(TPaintbox)
  private
    { Private declarations }
    FMain : TUnter;
  protected
    { Protected declarations }
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure Upgrade(Sender: TObject);

  published
    { Published declarations }
    property Main : TUnter read FMain write FMain;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('My Own', [TTestOwner]);
end;

{ TTestOwner }

constructor TTestOwner.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  FMain := TUnter.Create;
  FMain.OnChange := Upgrade;
end;

destructor TTestOwner.Destroy;
begin
  FMain.Free;
  inherited Destroy;
end;

procedure TTestOwner.Upgrade(Sender: TObject);
begin
  Self.Canvas.TextOut(Self.FMain.FZahl,1,'Hallo');
end;

{ TUnter }

procedure TUnter.Change;
begin
  if Assigned(FOnChange) then
    FOnChange(Self);
end;

procedure TUnter.SetZahl(const Value: Integer);
begin
  FZahl := Value;
  Change;
end;

end.

[Flocke]

Wieso willst du denn einen "published" Event "OnChange" machen, wenn du ihn direkt wieder belegst. Folgende Zeilen sollten dein Problem auch lösen (nicht getestet). Wie gesagt, wenn du alles unter ein type schreibst, dann kannst du "TTestOwner" forward deklarieren.

Delphi-Quellcode:

unit TestOwner;

interface

uses
  Windows, Messages, SysUtils, Classes, Controls, ExtCtrls;

type
  TTestOwner = class;

  TUnter = class(TPersistent)
  private
    FOwner: TTestOwner;
    FZahl : Integer;
    procedure SetZahl(const Value: Integer);
  protected
    procedure Change; virtual;
  public
    constructor Create(AOwner: TTestOwner);
    property Owner : TTestOwner read FOwner;
  published
    property Zahl : Integer read FZahl write SetZahl;
  end;

  TTestOwner = class(TPaintbox)
  private
    { Private declarations }
    FMain : TUnter;
  protected
    { Protected declarations }
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure Upgrade(Sender: TObject);

  published
    { Published declarations }
    property Main : TUnter read FMain write FMain;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('My Own', [TTestOwner]);
end;

{ TTestOwner }

constructor TTestOwner.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  FMain := TUnter.Create(Self);
end;

destructor TTestOwner.Destroy;
begin
  FMain.Free;
  inherited Destroy;
end;

procedure TTestOwner.Upgrade(Sender: TObject);
begin
  Self.Canvas.TextOut(Self.FMain.FZahl,1,'Hallo');
end;

{ TUnter }

constructor TUnter.Create(AOwner: TTestOwner);
begin
  inherited Create;
  FOwner := AOwner;
end;

procedure TUnter.Change;
begin
  FOwner.Upgrade;
end;

procedure TUnter.SetZahl(const Value: Integer);
begin
  if Value <> FZahl then
  begin
    FZahl := Value;
    Change;
  end;
end;

end.