没有骗大家吧说了给大家派高分已经有很多的朋友得了。高分征答新问题？(dyydyy)

Question

TPenMode = (pmBlack, pmWhite, pmNop, pmNot, pmCopy, pmNotCopy, pmMergePenNot, pmMaskPenNot, pmMergeNotPen, pmMaskNotPen, pmMerge, pmNotMerge, pmMask, pmNotMask, pmXor, pmNotXor)canvas.pen.mode:=pmXor;

Answer 1

(OnTimer:)
canvas.pen.mode = pmXor;
Canvas.MoveTo(Oldx1,Oldy1);
Canvas.LineTo(Oldx2,Oldy2);
Canvas.MoveTo(Newx1,Newy1);
Canvas.LineTo(Newx2,Newy2);
Oldx1 := Newx1;
Oldx2 := Newx2;
Oldy1 := Newy1;
Oldy2 := Newy2;