再學 GDI+[67]: 路徑畫刷(7) - 畫個五角星

本例效果圖:

　　代碼1:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs;
type
　TForm1 = class(TForm)
　　procedure FormPaint(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormPaint(Sender: TObject);
const
　pt: TPoint = (X:130; Y:130);
　r = 120;
　colors: array[0..0] of TGPColor = (aclRed);
var
　g: TGPGraphics;
　p: TGPPen;
　path: TGPGraphicsPath;
　pb: TGPPathGradIEntBrush;
　pts: array[0..4] of TGPPoint;
　radian: Single;
　i,num: Integer;
begin
　for i := 0 to 4 do
　begin
　　radian := i * (360*2/5) * (Pi/180);
　　pts[i].X := pt.X + Round(Sin(radian) * r);
　　pts[i].Y := pt.Y - Round(Cos(radian) * r);
　end;
　g := TGPGraphics.Create(Canvas.Handle);
　path := TGPGraphicsPath.Create;
　path.AddPolygon(PGPPoint(@pts), Length(pts));
　pb:= TGPPathGradIEntBrush.Create(path);
　num := Length(colors);
　pb.SetSurroundColors(@colors, num);
　pb.SetCenterColor(aclYellow);
　{描個邊}
　p := TGPPen.Create(aclYellow);
　g.SetSmoothingMode(SmoothingModeAntiAlias);
　g.DrawPath(p, path);
　g.FillPath(pb, path);
　pb.Free;
　path.Free;
　p.Free;
　g.Free;
end;
end.代碼2:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs;
type
　TForm1 = class(TForm)
　　procedure FormPaint(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormPaint(Sender: TObject);
const
　pt: TPoint = (X:130; Y:130);
　r = 120;
　colors: array[0..0] of TGPColor = (aclRed);
var
　g: TGPGraphics;
　p: TGPPen;
　path: TGPGraphicsPath;
　pb: TGPPathGradIEntBrush;
　pts: array[0..9] of TGPPoint;
　radian: Single;
　i,num: Integer;
　rx: Single;
begin
　for i := 0 to 9 do
　begin
　　rx := r;
　　if Odd(i) then rx := r * (1- (Sqrt(5)-1)/2); {(Sqrt(5)-1)/2 是黃金分割點, 約為 0.618}
　　radian := i * (360/10) * (Pi/180);
　　pts[i].X := pt.X + Round(Sin(radian) * rx);
　　pts[i].Y := pt.Y - Round(Cos(radian) * rx);
　end;
　g := TGPGraphics.Create(Canvas.Handle);
　path := TGPGraphicsPath.Create;
　path.AddPolygon(PGPPoint(@pts), Length(pts));
　pb:= TGPPathGradIEntBrush.Create(path);
　num := Length(colors);
　pb.SetSurroundColors(@colors, num);
　pb.SetCenterColor(aclYellow);
　{描個邊}
　p := TGPPen.Create(aclYellow);
　g.SetSmoothingMode(SmoothingModeAntiAlias);
　g.DrawPath(p, path);
　g.FillPath(pb, path);
　pb.Free;
　path.Free;
　p.Free;
　g.Free;
end;
end.窗體文件:object Form1: TForm1
　Left = 0
　Top = 0
　Caption = 'Form1'
　ClIEntHeight = 238
　ClIEntWidth = 259
　Color = clBtnFace
　Font.Charset = DEFAULT_CHARSET
　Font.Color = clWindowText
　Font.Height = -11
　Font.Name = 'Tahoma'
　Font.Style = []
　OldCreateOrder = False
　Position = poDesktopCenter
　OnPaint = FormPaint
　PixelsPerInch = 96
　TextHeight = 13
end