delphi 创建异形窗口[3]

unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;
type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
    procedure FormDblClick(Sender: TObject);
  end;
var
  Form1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button1Click(Sender: TObject);
var
  rgn: HRGN;
begin
  BeginPath(Canvas.Handle);
  SetBKMode(Canvas.Handle, TRANSPARENT);
  Canvas.Font.Size := 56;
  Canvas.Font.Style := [fsBold];
  Canvas.TextOut(12, 12, 'Delphi');
  EndPath(Canvas.Handle);
  rgn := PathToRegion(Canvas.Handle);
  Self.Color := clRed;
  SetWindowRgn(Handle, rgn, True);
end;
procedure TForm1.FormDblClick(Sender: TObject);
begin
  Close;
end;
end.

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 206
  ClientWidth = 339
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnDblClick = FormDblClick
  PixelsPerInch = 96
  TextHeight = 13
  object Button1: TButton
    Left = 136
    Top = 112
    Width = 75
    Height = 25
    Caption = 'Button1'
    TabOrder = 0
    OnClick = Button1Click
  end
end