Punkte verbinden - Lösung

unit mPunkteVerbinden;

interface

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

type
  TForm1 = class(TForm)
    Image1: TImage;
    btLoeschen: TButton;
    btGrenzeRechts: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Image1MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure btLoeschenClick(Sender: TObject);
    procedure btGrenzeRechtsClick(Sender: TObject);
  private
    { Private-Deklarationen }
    punkteX, punkteY: Array[1..20] of Integer;
    index: Integer;
  public
    { Public-Deklarationen }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Image1.Canvas.Rectangle(0,0,Image1.Width,Image1.Height);
  index := 1;
end;

procedure TForm1.Image1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var i: Integer;
begin
  if index <= 20 then
  begin
    punkteX[index] := X;
    punkteY[index] := Y;
    for i:=1 to index-1 do
    begin
      Image1.Canvas.MoveTo(X,Y);
      Image1.Canvas.LineTo(punkteX[i], punkteY[i])
    end;
    Inc(index)
  end;
end;

procedure TForm1.btLoeschenClick(Sender: TObject);
begin
  Image1.Canvas.Rectangle(0,0,Image1.Width,Image1.Height);
  index:=1;
end;

procedure TForm1.btGrenzeRechtsClick(Sender: TObject);
var xmax, i: Integer;
begin
  xmax := 0;
  for i:=1 to index-1 do
    if punkteX[i] > xmax then
      xmax := punkteX[i];
  with Image1.Canvas do
  begin
    MoveTo(xmax,0);
    LineTo(xmax,Image1.Height);
  end;
end;

end.