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
{$R *.dfm}
procedure
TForm1.btn1Click(Sender: TObject);
begin
showmessage('方法指针的长度是:'+Inttostr(SizeOf(TEvent)));
showmessage('函数指针的长度是:'+Inttostr(SizeOf(TProc)));
end;
//函数指针是指向函数的32位指针，占4个字节。
//过程的指针结构如下
// PProc
= ^TProc;//过程指针
// TProc = record
// Code:
Pointer;//指向过程的代码
// end;
//方法指针是指向一个结构。方法的指针结构如下
//
PMethod = ^TMethod;//方法指针
// TMethod = record
// Code:
Pointer;//指向方法的代码
//
Data: Pointer;//指向对象的数据
// end;
end.
interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls,
Forms,
Dialogs, StdCtrls;
type TEvent = procedure ()
of object;
TProc = procedure();
TForm1 = class(TForm)
btn1: TButton;
procedure btn1Click(Sender: TObject);
private { Private declarations }
public { Public declarations } end;
var Form1: TForm1;
implementation{$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.
