再学 GDI+[67]: 路径画刷(7) - 画个五角星

本例效果图:

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代码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);



  {描个边}

  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.


 
   

代码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 是黄金分割点, 约为 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);



  {描个边}

  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.


 
   

窗体文件:

---

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