WinAPI: PathToRegion 将路径转换为区域

本例效果图:

---

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}

procedure TForm1.FormPaint(Sender: TObject);
const
  str = 'Delphi';
var
  Rgn: HRGN;
  x,y: Integer;
begin
  Canvas.Font.Size := 68;
  Canvas.Font.Style := [fsBold];
  SetBkMode(Canvas.Handle, TRANSPARENT);

  x := (ClientWidth - Canvas.TextWidth(str)) div 2;
  y := (ClientHeight - Canvas.TextHeight(str)) div 3;

  {建立路径}
  BeginPath(Canvas.Handle);
  Canvas.TextOut(x, y, str);
  EndPath(Canvas.Handle);

  {将路径转换为区域}
  Rgn := PathToRegion(Canvas.Handle);

  {绘制}
  Canvas.Brush.Color := clSilver;
  Canvas.Brush.Style := bsDiagCross;
  FillRgn(Canvas.Handle, Rgn, Canvas.Brush.Handle);
  Canvas.Brush.Color := clRed;
  Canvas.Brush.Style := bsSolid;
  FrameRgn(Canvas.Handle, Rgn, Canvas.Brush.Handle, 1, 1);

  DeleteObject(Rgn);
end;

end.