我做了一個類似小畫家的程式..我碰到一個問題
例如我在Image畫了四條線，我要用ㄧ個button鍵當作復原的功能，還原成三條線，這樣的復原功能程式要怎麼寫呢?用undo?還要用陣列?各位高手教教我吧~!

印像中可以使用Memento,去實現. undo 功能

標頭檔
bool MDown;
int OldX,OldY;

//-------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
int x1,y1,x2,y2;
x1=10;
y1=10;
x2=100;
y2=100;
Image1->Canvas->MoveTo(x1,y1);
Image1->Canvas->LineTo(x2,y2);
}
//--------------------------
void __fastcall TForm1::Image1MouseUp(TObject *Sender, TMouseButton Button,
TShiftState Shift, int X, int Y)
{
MDown=false;
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Image1MouseMove(TObject *Sender, TShiftState Shift,
int X, int Y)
{
if(MDown==true)
{ Image1->Canvas->MoveTo(OldX,OldY);
Image1->Canvas->LineTo(X,Y);
OldX=X;
OldY=Y;
}
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
MDown=false;
DoubleBuffered=true;
}



你說的那個語法要怎麼使用呢??