PaintBox

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls, ExtCtrls;type  TForm1 = class(TForm)    PaintBox1: TPaintBox;    Panel1: TPanel;    Button1: TButton;    procedure Button1Click(Sender: TObject);    procedure PaintBox1MouseDown(Sender: TObject; Button: TMouseButton;      Shift: TShiftState; X, Y: Integer);    procedure FormCreate(Sender: TObject);  private    { Private declarations }  public    { Public declarations }  end;var  Form1: TForm1;  oldX:integer;  oldY:integer;  count:integer;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);begin with PaintBox1.Canvas do  begin    brush.Color:=clWhite;    FillRect(rect(0,0,PaintBox1.Width,PaintBox1.Height));  end;end;procedure TForm1.PaintBox1MouseDown(Sender: TObject; Button: TMouseButton;  Shift: TShiftState; X, Y: Integer);var  OldBrushColor: TColor;  OldpenColor: TColor;begin  with PaintBox1.Canvas do  begin  //if obj.showed then  //begin      OldBrushColor:=brush.color;      OldpenColor:=pen.color;    if {obj.Selected} Not (count>0) then    begin        Pen.Color:=rgb(255,0,0);    end;      Brush.Color:=$00FF31FF;      Ellipse(X-10,Y-10,X+10,Y+10);      Pen.Color:=$00FF31FF;    if {obj.TypeNo>0}count>0 then    begin        //moveTo(obj.CenterX,obj.CenterY);        //lineTo(GetObj(obj.FNode).CenterX,GetObj(obj.FNode).CenterY);        moveTo(oldX,oldY);        lineTo(X,Y);    end;      oldX:=X;      oldY:=Y;      Inc(count);      pen.color:=OldpenColor;      brush.color:=OldBrushColor;  //end;  end;end;procedure TForm1.FormCreate(Sender: TObject);begincount:=0;end;end.