delphi 函数指针 方法指针

unit Unit1;

interface

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

type
  
TEvent = procedure ()
of object;
   TProc
= procedure();

  
TForm1 = class(TForm)
     btn1:
TButton;
     procedure
btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  
end;

var
  
Form1: TForm1;

implementation

{$R *.dfm}

procedure
TForm1.btn1Click(Sender: TObject);
begin
  
showmessage('方法指针的长度是:'+Inttostr(SizeOf(TEvent)));
  
showmessage('函数指针的长度是:'+Inttostr(SizeOf(TProc)));
end;

//函数指针是指向函数的32位指针，占4个字节。
//过程的指针结构如下
//   PProc
= ^TProc;//过程指针
//　TProc = record
//　　Code:
Pointer;//指向过程的代码
//　end;
//方法指针是指向一个结构。方法的指针结构如下
//  
PMethod = ^TMethod;//方法指针
//　TMethod = record
//　　Code:
Pointer;//指向方法的代码
//    
Data: Pointer;//指向对象的数据
//　end;



end.