EReaderror bei einer komponente

[IIIMADDINIII]

hallöchen,
ich habe ien kleines problenchen:
Ich wollte mir eine eigene listebox schreiben welche an einer seite rund ist(Roundlist.pas). am anfang lief alles glatt bis ich die komponente benutzen wollte.
als ich das Form mit komponente laufen lassen wollte gab er mir immer drei fehler der klasse EReadError und danach wurde die anwendung beendet. erstaunlich jedoch ist das wenn ich die propertys ausklammere es sich starten lies nur jetzt sah ich die komponente nicht mehr. ich konnte auch auf Dem Project Hinzufügen gehen und Roundlist hinzufügen. dann lief auch alles wie es sollte.

hier ist die unit

Delphi-Quellcode:

unit roundlist;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, math;

type
  Troundlist = class(TCustomControl)
  private
    { Private-Deklarationen }
    selfcolor: TColor;
    selfshowwidth: Extended;
    selfY: integer;
    selfmousepoint: Boolean;
  protected
    { Protected-Deklarationen }
    procedure Paint; override;
    procedure MouseMove(Shift: TShiftState; X,Y: Integer); override;
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
    procedure MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer); override;
  public
    { Public-Deklarationen }
    constructor create (AOwner: TComponent); override;
    procedure setcolor(Color: TColor); virtual;
    procedure setshowwidth(Showwidth: Extended); virtual;
  published
    { Published-Deklarationen }
    property OnClick;
    Property OnMouseDown;
    property OnMouseMove;
    Property OnMouseUp;
    property OnEnter;
    Property OnExit;
    property OnKeyPress;
    property OnKeyDown;
    Property OnKeyUp;
    Property color: Tcolor read selfColor write SetColor;
    Property Showwidth: extended read selfShowwidth write setshowwidth;
  end;

procedure Register;

implementation

procedure Troundlist.Paint;
var
  Steigung, Xpos, YPos: extended;
  Uber: integer;
begin

  canvas.Pen.Color := selfcolor;
  Canvas.Brush.Color := selfColor;
  steigung := height / (width * selfshowwidth);
  Uber := round(((height / 2) / sqrt(((height / 2) * (height / 2)) - ((Width * selfshowwidth / 2 - Width) * Steigung * (Width * selfshowwidth / 2 - Width) * Steigung)) * (height / 2)) - (height / 2));
  Canvas.Ellipse(round(width - (width * selfshowwidth)),-Uber,width, height + Uber);
  if (((SelfY) - (height / 2)) / (uber - 6 + (height / 2)) >= -1) and (((SelfY) - (height / 2)) / (uber - 6 + (height / 2)) <= 1) then
  Xpos := cos(arcsin(((SelfY) - (height / 2)) / (uber - 6 + (height / 2)))) * (width * selfshowwidth / 2 + 6) - ((Width * selfshowwidth / 2) - Width) - 12
  else XPos := 0;
  if Xpos < (width * 0.05) then
  begin
    Xpos := Width * 0.05;
    YPos := sin(arccos((XPos + (width * selfshowwidth / 2 - width)) / (Width * selfshowwidth / 2))) * (uber + height / 2 - 6) + Height / 2;
    if selfY < Height / 2 then SelfY := round(height - YPos)
    else SelfY := round(YPos);
  end;
  canvas.Pen.Color := rgb(255, 255, 0);
  Canvas.Rectangle(round(Xpos - 4), selfY - 4, round(Xpos + 4), selfY + 4);
  canvas.Pen.Color := rgb(255, 243, 0);
  Canvas.Rectangle(round(Xpos - 3), selfY - 3, round(Xpos + 3), selfY + 3);
  canvas.Pen.Color := rgb(255, 231, 0);
  Canvas.Rectangle(round(Xpos - 2), selfY - 2, round(Xpos + 2), selfY + 2);
  canvas.Pen.Color := rgb(255, 219, 0);
  Canvas.Rectangle(round(Xpos - 1), selfY - 1, round(Xpos + 1), selfY + 1);
end;

constructor Troundlist.create(AOWner: TComponent);
begin
  inherited create (AOwner);
  selfcolor := clWhite;
  selfshowwidth := 2;
  SelfY := 0;
  setBounds(0,0,100,200);
end;

procedure TRoundlist.MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  SelfMousePoint := true;
end;

procedure TRoundlist.MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
var
  XPos: Extended;
  Uber: integer;
begin
  inherited MouseDown(Button, Shift, X, Y);
  Uber := round(((height / 2) / sqrt(((height / 2) * (height / 2)) - ((Width * selfshowwidth / 2 - Width) * Steigung * (Width * selfshowwidth / 2 - Width) * Steigung)) * (height / 2)) - (height / 2));
  Xpos := cos(arcsin(((Y) - (height / 2)) / (uber - 6 + (height / 2)))) * (width * selfshowwidth / 2 + 6) - ((Width * selfshowwidth / 2) - Width) - 12;
  if (X >= XPos - 6) and (X <= XPos + 6) then
  begin
    SelfMousePoint := true;
    selfY := Y;
  end;
  paint;
end;

procedure TRoundlist.MouseMove(Shift: TShiftState; X,Y: Integer);
begin
  inherited MouseMove (Shift, X, Y);
  if selfMovepoint then SelfY := Y;
  Paint;
end;

procedure TRoundlist.setshowwidth(showwidth: Extended);
begin
  selfshowwidth := showwidth;
  rEPAINT;
end;

procedure TRoundlist.setcolor(color: TColor);
begin
  selfcolor := Color;
  Repaint;
end;

procedure Register;
begin
  RegisterComponents('Beispiele', [Troundlist]);
end;

end.