再學 GDI+[77]: 區域(6) - GetRegionScans - 獲取區域中的所有矩形

本例效果圖:

　　代碼文件:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs, StdCtrls;
type
　TForm1 = class(TForm)
　　procedure FormPaint(Sender: TObject);
　　procedure FormClick(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormPaint(Sender: TObject);
var
　g: TGPGraphics;
　b: TGPSolidBrush;
　path: TGPGraphicsPath;
　rgn: TGPRegion;
　Matrix: TGPMatrix;
　RectCount: Integer;
　rts: array of TGPRect;
　i: Integer;
begin
　g := TGPGraphics.Create(Canvas.Handle);
　b := TGPSolidBrush.Create(MakeColor(50, 0, 0, 255));
　path := TGPGraphicsPath.Create;
　path.AddEllipse(MakeRect(20, 10, ClientWidth-40, ClIEntHeight-20));
　rgn := TGPRegion.Create(path);
　Matrix := TGPMatrix.Create; {它在本例中只是個擺設, 因為參選需要}
　RectCount := rgn.GetRegionScansCount(Matrix);
　SetLength(rts, RectCount);
　rgn.GetRegionScans(Matrix, PGPRect(rts), RectCount);
　Randomize;
　for i := 0 to RectCount - 1 do
　begin
　　b.SetColor(ColorRefToARGB(Random($FFFFFF)));
　　g.FillRectangle(b, rts[i]);
　end;
　Matrix.Free;
　rgn.Free;
　path.Free;
　b.Free;
　g.Free;
end;
procedure TForm1.FormClick(Sender: TObject);
begin
　Repaint;
end;
end.窗體文件:object Form1: TForm1
　Left = 0
　Top = 0
　Caption = 'Form1'
　ClIEntHeight = 217
　ClIEntWidth = 219
　Color = clBtnFace
　Font.Charset = DEFAULT_CHARSET
　Font.Color = clWindowText
　Font.Height = -11
　Font.Name = 'Tahoma'
　Font.Style = []
　OldCreateOrder = False
　Position = poDesktopCenter
　OnClick = FormClick
　OnPaint = FormPaint
　PixelsPerInch = 96
　TextHeight = 13
end