This is with Delphi Berlin 10.1 Update 2

The following works (I get a line drawn):

brush := TStrokeBrush.Create(TBrushKind.Solid, TAlphaColors.Lightgray);
brush.Thickness := 2;
with Canvas do
begin
BeginUpdate;
DrawLine(PointF(10, 10), PointF(100, 10), 1, brush);
EndUpdate;
end;

The following does not work:

with Canvas do
begin
BeginUpdate;
Stroke.Color := TAlphaColors.Black;
Stroke.Thickness := 2.0;
DrawLine(PointF(10, 10), PointF(100, 10), 1);
EndUpdate;
end;

Why can’t I use the 2nd one? How can I get it to work, or should I stick to creating a stroke brush as in the first example?

I’ve included a minimal application:

main.pas

unit main;

interface

uses
System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs, FMX.Objects;

type
TMainForm = class(TForm)
PaintBox: TPaintBox;
procedure OnPaint(Sender: TObject; Canvas: TCanvas);
private
{ Private declarations }
public
{ Public declarations }
end;

var
MainForm: TMainForm;

implementation

{$R *.fmx}

procedure TMainForm.OnPaint(Sender: TObject; Canvas: TCanvas);
begin
with Canvas do
begin
BeginUpdate;
Stroke.Color := TAlphaColors.Black;
Stroke.Thickness := 2.0;
DrawLine(PointF(10, 10), PointF(100, 10), 1);
EndUpdate;
end;
end;

end.

main.fmx:

object MainForm: TMainForm
Left = 0
Top = 0
Caption = ‘Form1’
ClientHeight = 480
ClientWidth = 640
FormFactor.Width = 320
FormFactor.Height = 480
FormFactor.Devices = [Desktop]
DesignerMasterStyle = 0
object PaintBox: TPaintBox
Position.X = 16.000000000000000000
Position.Y = 16.000000000000000000
Size.Width = 609.000000000000000000
Size.Height = 449.000000000000000000
Size.PlatformDefault = False
OnPaint = OnPaint
end
end

test.dpr:

program test;

uses
System.StartUpCopy,
FMX.Forms,
main in ‘main.pas’ {MainForm};

{$R *.res}

begin
Application.Initialize;
Application.CreateForm(TMainForm, MainForm);
Application.Run;
end.