FireMonkey - 在Windows中绘制没有消除锯齿的1像素线

Question

我没有成功尝试绘制1像素线。我尝试将表单中的QDockWidget* dw = new QDockWidget; QWidget* tw1 = new TestWidget; QWidget* tw2 = new TestWidget; dw->setWidget(tw1); dw->setWidget(tw2); tw1->setParent(0); delete dw; // dw and tw2 deleted here, but not tw1 参数设置为所有三个可用选项，但这不会改变结果：始终获得具有抗锯齿功能的行。相反，不知何故，Quality类绘制了一个干净的1像素宽度边框，这意味着可以禁用抗锯齿模式。问题是如何。下面是我使用的代码示例：

tRectangle

procedure tMyLine.Paint; begin with Canvas do begin Stroke.Cap := Flat; Stroke.Color := tAlphaColor.Blue; Stroke.Join := Miter; Stroke.Kind := Solid; Stroke.Thickness := 1; BeginScene; DrawLine (tPointF (10, 10), tPointF (100, 10), 1); EndScene; end; end; 小于一个也不起作用。

Answer 1

使用表单和paintbox的这些设置（偏离默认值）： （顺便说一下，使用Delphi 10.1 Berlin，我没有安装东京）

object Form24: TForm24
  Left = 0
  Top = 0
  Caption = 'Form24'
  ClientHeight = 216
  ClientWidth = 311
  Quality = HighPerformance
  FormFactor.Width = 320
  FormFactor.Height = 480
  FormFactor.Devices = [Desktop]
  DesignerMasterStyle = 0
  object PaintBox1: TPaintBox
    Position.X = 8.000000000000000000
    Position.Y = 8.000000000000000000
    Size.Width = 200.000000000000000000
    Size.Height = 200.000000000000000000
    Size.PlatformDefault = False
    OnPaint = PaintBox1Paint
  end

注意：Quality = HighPerformance，而不是HighQuality

以下代码

procedure TForm24.PaintBox1Paint(Sender: TObject; Canvas: TCanvas);
var
  a: integer;
begin
  Canvas.BeginScene;
  try
    Canvas.Stroke.Color := TAlphaColorRec.Black;
    Canvas.Stroke.Kind := TBrushKind.Solid;
    Canvas.Stroke.Dash := TStrokeDash.solid;

    for a := 0 to 10 do
      Canvas.DrawLine(PointF(a * 20, 0), PointF(a * 20, 200), 1);

    for a := 0 to 10 do
      Canvas.DrawLine(PointF(0, a * 20 + 0), PointF(200, a * 20), 1);


    Canvas.DrawLine(PointF(0, 0), PointF(200, 200), 1);
    Canvas.DrawEllipse(RectF(5, 5, 195, 195), 1);

    Canvas.Stroke.Dash := TStrokeDash.Solid;
    Canvas.Stroke.Color := TAlphaColorRec.Red;
    Canvas.DrawRect(RectF(5, 5, 195, 195), 0, 0, [], 1);
  finally
    Canvas.EndScene;
  end;
end;

产生此结果

Answer 2

通过将坐标设置为整数+ 0.5，我能够对垂直和水平线执行此操作。看来，如果使用整数坐标，则会将线放置在像素边界上，但是通过添加0.5会将线放置在像素的中间。

DrawLine（tPointF（10.5，10.5），tPointF（100.5，10.5），1）;