uframergn.pas

Delphi Win32核心API参考光盘源码 本书包含了常用的Windows API函数

unit UFrameRgn;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private

  public
    { Public declarations }
  end;

var
  Form1: TForm1;

  implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
  RegionHandle: HRGN;                 // the region handle
  PointsArray: array[0..5] of TPoint; // points defining the region
begin
  {define the region}
  PointsArray[0].X := 50;
  PointsArray[0].y := 50;
  PointsArray[1].x := 100;
  PointsArray[1].y := 50;
  PointsArray[2].x := 125;
  PointsArray[2].y := 75;
  PointsArray[3].x := 100;
  PointsArray[3].y := 100;
  PointsArray[4].x := 50;
  PointsArray[4].y := 100;
  PointsArray[5].x := 25;
  PointsArray[5].y := 75;

  {create the polygonal region}
  RegionHandle := CreatePolygonRgn(PointsArray, 6, ALTERNATE);

  {frame the region in black}
  Canvas.Brush.Color := clBlack;
  FrameRgn(Canvas.Handle, RegionHandle, Canvas.Brush.Handle, 2, 2);
end;

end.