Komponent

Hvorfor kan jeg ikke bruge den kode her:

Kode 

procedure GrayScale;
var
 Gray, X, Y: Integer;
 PByte:      PByteArray;
begin
 with [u]FImage.Picture.Bitmap[/u] do
 begin
   for Y := 0 to Height -1 do
   begin
     PByte := ScanLine[Y];
     for X := 0 to Width -1 do
     begin
       Gray := Round(PByte[X * 3] * 0.3 + PByte[X * 3 + 1] * 0.59 + PByte[X * 3 + 2] * 0.11);
       PByte[X * 3] := Gray;
       PByte[X * 3 + 1] := Gray;
       PByte[X * 3 + 2] := Gray;
     end;
   end;
 end;
 [u]FImage.Refresh;[/u]
end;

Den siger: "Undeclared identifier: FImage".

GrayScale er ikke en del af din klasse og så kender den ikke FImage. Hvis du bare laver GrayScale til en del af klassen burde det virke.

Husk også lige at create og free'e FImage i klassens constructor og destructor ellers får du en access violation hver gang du forsøger at bruge FImage.

Hvordan får jeg det understreget til at virke i en komponent, På den måde som vist?

Kode 

unit Komponent;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, JPEG,
  Dialogs, StdCtrls, Forms, extctrls;

type
  TEffect = class(TComponent)
  private
    { Private declarations }
    FImage:       TImage;
    Procedure size;
 
  protected
    { Protected declarations }

  public
    { Public declarations }
    Constructor Create(AOwner: TComponent); override;
    Destructor Destroy; override;

  published
    { Published declarations }
    Property Image: TImage read FImage write FImage;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('PDJ', [TKomponent]);
end;

constructor TKomponent.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
end;

destructor TKomponent.Destroy;
begin
  inherited Destroy;
end;

procedure Size;
end;
  [u]TKomponent.Image.Picture.Bitmap.Height := 100;
  TKomponent.Image.Picture.Bitmap.Width := 100;[/u]
end.

FImage.Picture.Bitmap.Height := 100;
FImage.Picture.Bitmap.Width := 100;

Emil Melgaard
emil.melgaard@private.dk

Hvordan får jeg det understreget til at virke i en komponent, På den måde som vist?

Kode 

unit Komponent;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, JPEG,
  Dialogs, StdCtrls, Forms, extctrls;

type
  TEffect = class(TComponent)
  private
    { Private declarations }
    FImage:       TImage;
    Procedure size;
 
  protected
    { Protected declarations }

  public
    { Public declarations }
    Constructor Create(AOwner: TComponent); override;
    Destructor Destroy; override;

  published
    { Published declarations }
    Property Image: TImage read FImage write FImage;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('PDJ', [TKomponent]);
end;

constructor TKomponent.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
end;

destructor TKomponent.Destroy;
begin
  inherited Destroy;
end;

procedure Size;
end;
  [u]TKomponent.Image.Picture.Bitmap.Height := 100;
  TKomponent.Image.Picture.Bitmap.Width := 100;[/u]
end.

FImage.Picture.Bitmap.Height := 100;
FImage.Picture.Bitmap.Width := 100;

Emil Melgaard
emil.melgaard@private.dk

Hvorfor kan jeg ikke bruge den kode her:

procedure GrayScale;
var
 Gray, X, Y: Integer;
 PByte:      PByteArray;
begin
 with [u]FImage.Picture.Bitmap[/u] do
 begin
   for Y := 0 to Height -1 do
   begin
     PByte := ScanLine[Y];
     for X := 0 to Width -1 do
     begin
       Gray := Round(PByte[X * 3] * 0.3 + PByte[X * 3 + 1] * 0.59 + PByte[X * 3 + 2] * 0.11);
       PByte[X * 3] := Gray;
       PByte[X * 3 + 1] := Gray;
       PByte[X * 3 + 2] := Gray;
     end;
   end;
 end;
 [u]FImage.Refresh;[/u]
end;

Den siger: "Undeclared identifier: FImage".