简单画板程序C++ Builder

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
#include "Unit2.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma link "ShockwaveFlashObjects_OCX"
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::RadioGroup1Click(TObject *Sender)
{
 switch(RadioGroup1->ItemIndex)
 {
 case 0:Image1->Canvas->Pen->Style=psSolid; break;
 case 1:Image1->Canvas->Pen->Style=psDashDot;  break;
 case 2:Image1->Canvas->Pen->Style=psDot;   break;
 }
}
//---------------------------------------------------------------------------
void __fastcall TForm1::ColorBox1Change(TObject *Sender)
{

Image1->Canvas->Pen->Color=ColorBox1->Selected;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Image1MouseMove(TObject *Sender, TShiftState Shift,
      int X, int Y)
{

  if(flag)
{

     Image1->Canvas->Pen->Mode=pmNotXor;




if(RadioGroup2->ItemIndex==0)
 {
   Image1->Canvas->Rectangle(A.x,A.y,B.x,B.y);
  B.x=X;
  B.y=Y;

  Image1->Canvas->Rectangle(A.x,A.y,B.x,B.y);


 }

if(RadioGroup2->ItemIndex==1)
 {
  Image1->Canvas->Ellipse(A.x,A.y,X,Y);
  B.x=X;