unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ComCtrls;
type
TForm1 = class(TForm)
TrackBar1: TTrackBar;
procedure FormPaint(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure TrackBar1Change(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormCreate(Sender: TObject);
begin
TrackBar1.Height := 23;
TrackBar1.ShowSelRange := False;
TrackBar1.Min := -5000;
TrackBar1.Max := 5000;
TrackBar1.Position := 25;
TrackBar1.PageSize := 5;
end;
procedure TForm1.FormPaint(Sender: TObject);
var
g: TGPGraphics;
p: TGPPen;
path: TGPGraphicsPath;
f: Single;
begin
g := TGPGraphics.Create(Canvas.Handle);
p := TGPPen.Create(aclBlue, 2);
path := TGPGraphicsPath.Create;
path.AddEllipse(20, 20, ClientWidth-40, ClIEntHeight- 80);
f := TrackBar1.Position / 100;
path.Flatten(nil, f);
Text := Format('%f', [f]);
g.DrawPath(p, path);
path.Free;
p.Free;
g.Free;
end;
procedure TForm1.TrackBar1Change(Sender: TObject);
begin
Repaint;
end;
end.
