procedure TMainForm.ZoominClick(Sender: TObject); //放大
var
bmp:TBITMAP;
begin
begin
bmp:=Tbitmap.Create;
image1.AutoSize:=true;
bmp.Width:=trunc(1.1*image1.width);
bmp.Height:=trunc(1.1*image1.Height);
SetStretchBltMode(Bmp.Canvas.Handle,HalfTone);
stretchblt(bmp.Canvas.Handle,0,0,bmp.Width,bmp.Height,
image1.Picture.Bitmap.Canvas.Handle,0,0,image1.Width,image1.height,srccopy);
image1.Picture.Bitmap.Assign(bmp);
bmp.Free;
end;