Paint on Bitmap

uses ColorGrd

private
    { Private-Deklarationen }
    fBitmap: TBitmap;
    fDown: boolean;
    
//

procedure TForm1.FormCreate(Sender: TObject);
begin
   fBitmap:= TBitmap.create;
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
   fBitmap.free
end;

procedure TForm1.FormResize(Sender: TObject);
begin
   fBitmap.width:=Paintbox1.width;
   fBitmap.height:=Paintbox1.Height;
end;

procedure TForm1.PaintBox1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
   if fDown then begin
     case colorgrid1.ForegroundIndex of
        0: fBitmap.Canvas.Pixels[x,y]:=clBlack;
        1: fBitmap.Canvas.Pixels[x,y]:=clMaroon;
        2: fBitmap.Canvas.Pixels[x,y]:=clGreen;
        3: fBitmap.Canvas.Pixels[x,y]:=clOlive;
        4: fBitmap.Canvas.Pixels[x,y]:=clNavy;
        5: fBitmap.Canvas.Pixels[x,y]:=clPurple;
        6: fBitmap.Canvas.Pixels[x,y]:=clTeal;
        7: fBitmap.Canvas.Pixels[x,y]:=clSilver;
        8: fBitmap.Canvas.Pixels[x,y]:=clGray;
        9: fBitmap.Canvas.Pixels[x,y]:=clRed;
        10: fBitmap.Canvas.Pixels[x,y]:=clLime;
        11: fBitmap.Canvas.Pixels[x,y]:=clYellow;
        12: fBitmap.Canvas.Pixels[x,y]:=clBlue;
        13: fBitmap.Canvas.Pixels[x,y]:=clFuchsia;
        14: fBitmap.Canvas.Pixels[x,y]:=clAqua;
        15: fBitmap.Canvas.Pixels[x,y]:=clWhite;
      end;
      paintbox1paint(sender);
   end;
end;

procedure TForm1.PaintBox1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
   fDown:=true;
end;

procedure TForm1.PaintBox1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
   fDown:=false;
end;

procedure TForm1.PaintBox1Paint(Sender: TObject);
begin
   Paintbox1.Canvas.draw(0,0,fBitmap);
end;

Bitmap Laden :

procedure TForm1.Button1Click(Sender: TObject);
begin
   if OpenPictureDialog1.execute then begin
      SavePictureDialog1.FileName:=OpenPictureDialog1.FileName;
      fBitmap.LoadFromFile(OpenPictureDialog1.FileName);
      FormResize(Sender);
      Paintbox1.invalidate;
   end;
end;

Bitmap Speichern :

procedure TForm1.Button2Click(Sender: TObject);
begin
   if SavePictureDialog1.execute then begin
      OpenPictureDialog1.FileName:=SavePictureDialog1.FileName;
      fBitmap.SaveToFile(SavePictureDialog1.FileName);
   end;
end;