WinAPI: CreatePolygonRgn - 建立多边形区域

本例效果图:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    procedure FormPaint(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormPaint(Sender: TObject);
var
  ps: array[0..9] of TPoint;
  Rgn: HRGN;
begin
  ps[0] := Point(120, 5);
  ps[1] := Point(140, 70);
  ps[2] := Point(210, 70);
  ps[3] := Point(150, 100);
  ps[4] := Point(180, 175);
  ps[5] := Point(120, 120);
  ps[6] := Point(60, 175);
  ps[7] := Point(90, 100);
  ps[8] := Point(30, 70);
  ps[9] := Point(100, 70);

  {建立多边形区域}
  Rgn := CreatePolygonRgn(ps, Length(ps), WINDING);

  {填充区域}
  Canvas.Brush.Color := clSilver;
  Canvas.Brush.Style := bsCross;
  FillRgn(Canvas.Handle, Rgn, Canvas.Brush.Handle);

  {绘制区域边界}
  Canvas.Brush.Color := clRed;
  Canvas.Brush.Style := bsSolid;
  FrameRgn(Canvas.Handle, Rgn, Canvas.Brush.Handle, 2, 2);
  DeleteObject(Rgn);
end;

end.