Delphi中Self问题和方法赋值问题

开发环境Delphi7

self报错问题

unit Unit1;

interface

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

type
 
  
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Panel1: TPanel;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);

  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

procedure sssss(aObj,Sender: Tobject);

implementation

uses
  Unit3;

{$R *.dfm}
procedure sssss(aObj,Sender: Tobject);
begin
  ShowMessage(TForm(aObj).name); //如果Button4点击过 ，再点击Button2,这句也会报错  //和Button1Click中注释的那句一样
  ShowMessage(TForm(Sender).name);
  ShowMessage('000');
end;
procedure TForm1.Button1Click(Sender: TObject);
var
  s:Integer;
begin
  //为了证明Self赋值问题，self其实是一个隐形参数
  //ShowMessage(self.name);会报错
  ShowMessage(IntToStr(Integer(@self))); //这个比下面的这个Integer(@Sender)大四个字节
  ShowMessage(IntToStr(Integer(@Sender)));//这个比下面的这个Integer(@s)大四个字节
  ShowMessage(IntToStr(Integer(@s)));
  //由这几个地址充分证明了self是一个隐形参数
  //学过汇编应该清楚栈相关的问题，栈的内存大小是定死的，是由程序编译时就定义好了，集成开发环境都有对栈的大小进行设置；
  //栈是由高地址向低地址延伸的，比如当前栈顶地址为200208，压一个32位的Integer进去后，当前栈顶为200204
  //不做过多解释
  //仅做个笔记

  ShowMessage((Sender as TComponent ).name);
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  s:TNotifyEvent;
begin
  s:=Button1.onClick;
  sss(@s);
end;

procedure TForm1.Button4Click(Sender: TObject);
var
  s:TNotifyEvent;
begin
  @Button1.onClick:=@sssss;//把sssss赋值给Button1.onClick
end;

end.

unit Unit3;

interface

uses
  Classes,Forms;
  procedure sss(pp:Pointer);

implementation

uses
  Unit2;

procedure sss(pp:Pointer);
begin
  Form2:=TForm2.Create(Application);
  @Form2.OnMyProc:=pp;
  Form2.Show;
end;
end.

unit Unit2;

interface

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

type
  TForm2 = class(TForm)
    Button1: TButton;
    procedure FormDestroy(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    FOnMyProc:TNotifyEvent;
    { Private declarations }
  public
    property OnMyProc :TNotifyEvent read FOnMyProc write FOnMyProc;
    { Public declarations }
  end;

var
  Form2: TForm2;
implementation

{$R *.dfm}

procedure TForm2.FormDestroy(Sender: TObject);
begin
  OnMyProc:=nil;
end;

procedure TForm2.Button1Click(Sender: TObject);
begin
  OnMyProc(Sender );
end;

end.