The anonymous method in Delphi 2009 (reference to)

Before we can define the method type and then use the method by the variable of the method type, for example:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs;
type
　TForm1 = class(TForm)
　　procedure FormCreate(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
Type
　TFun = function(const num: Integer): Integer; {先定义一个方法类型}
　function MySqr(const num: Integer): Integer;　{再创建一个吻合上面类型的一个方法}
　begin
　　Result := num * num;
　end;
{测试}
procedure TForm1.FormCreate(Sender: TObject);
var
　fun: TFun;　{方法变量}
　n: Integer;
begin
　fun := MySqr;　　　　　　 {给变量赋值为相同格式的方法}
　n := fun(9);　　　　　　　{现在这个方法变量可以使用了}
　ShowMessage(IntToStr(n)); {81}
end;
end.This is done because there are times when the "method" needs to be taken as a parameter, such as:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs;
type
　TForm1 = class(TForm)
　　procedure FormCreate(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
Type
　TFun = function(const num: Integer): Integer; {先定义一个方法类型}
　function MySqr(const num: Integer): Integer;　{再创建一个吻合上面类型的一个方法}
　begin
　　Result := num * num;
　end;
　{把方法当作参数的方法}
　procedure MyProc(var x: Integer; fun: TFun);
　begin
　　x := fun(x);
　end;
{测试}
procedure TForm1.FormCreate(Sender: TObject);
var
　n: Integer;
begin
　n := 9;
　MyProc(n, MySqr);
　ShowMessage(IntToStr(n)); {81}
end;
end.Now Delphi 2009 can use the anonymous method (use reference to define the method type, and then use the Write method in the code), such as:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs;
type
　TForm1 = class(TForm)
　　procedure FormCreate(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
Type
　TFun = reference to function(const num: Integer): Integer; {用 reference 定义匿名方法类型}
procedure TForm1.FormCreate(Sender: TObject);
var
　fun: TFun;
　n: Integer;
begin
　{求平方}
　fun := function(const a: Integer): Integer {注意本行最后不能有 ; 号}
　begin
　　Result := a * a;
　end;
　n := fun(9);
　ShowMessage(IntToStr(n)); {81}
　{求倍数}
　fun := function(const a: Integer): Integer
　begin
　　Result := a + a;
　end;
　n := fun(9);
　ShowMessage(IntToStr(n)); {18}
end;
end.