我通过下面的程序段画线:
with self.canvas do begin
pen.color:=clBlack;
pen.width:=2;
MoveTo (x1,y1);
LineTo (x2,y2);
end;
现在我要通过点击button后能够擦除原来的线条然后重新画线要如何做?
with self.canvas do begin
pen.color:=clBlack;
pen.width:=2;
MoveTo (x1,y1);
LineTo (x2,y2);
end;
现在我要通过点击button后能够擦除原来的线条然后重新画线要如何做?
不太记了,我给你找一下;
procedure TForm1.ClearCanvas(ACanvas: TCanvas);
var
R : TRect;
begin
with ACanvas do
begin
Brush.Style := bsSolid;
Brush.Color := ClWhite;
GetWindowRect(Handle,R);
R.TopLeft := ScreenToClient(R.TopLeft);
R.BottomRight := ScreenToClient(R.BottomRight);
FillRect(R);
end;