Windows获取显示器缩放比例

先放代码：

function getScreenScale:double;
var
dc:HDC;
begin
  dc:= GetDC(0);
  result:= GetDeviceCaps(dc,LOGPIXELSX)/0.96/100;
  ReleaseDC(0,dc);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Label1.Caption := getScreenScale.ToString;
end;

测试结果：