unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure FormPaint(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
   Canvas.Pen.Color:=clRed;
   Canvas.Moveto(0,0);
   Canvas.Lineto(ClientWidth, ClientHeight);
   Canvas.Moveto(ClientWidth,0);
   Canvas.Lineto(0, ClientHeight);
end;
//lub rysowanie trwałe


procedure TForm1.FormPaint(Sender: TObject);
begin
{   Canvas.Pen.Color:=clRed;
   Canvas.Moveto(0,0);
   Canvas.Lineto(ClientWidth, ClientHeight);
   Canvas.Moveto(ClientWidth,0);
   Canvas.Lineto(0, ClientHeight);}
end;

end.
