如何将一个对象的值复制到另一个对象中(25分)

M

mycwcgr_temp

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• 2002-12-05

• #1

如何将一个对象的值复制到另一个对象中
下面两个对象myaa,mybb都是从Tobject继承的,没有assign方法,如何方便的将myaa中的所有属性值
复制到mybb中去？mybb:=myaa 仅仅复制了指针.

unit Unit1;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls;

type tbb=class(Tobject)
tindex:integer;
tstr:string
end;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
myaa:tbb;
mybb:tbb;
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;
implementation
{$R *.DFM}
procedure TForm1.Button1Click(Sender: TObject);
begin
myaa:=tbb.Create;
mybb:=tbb.create;
myaa.tindex:=5;
myaa.tstr:='cw';
mybb:=myaa;
{仅仅复制了指针}
//mybb.assign(aa);{不能执行，因为它们不是从TPersistent继承的}
end;

end.

 

Y

yh

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• 2002-12-05

• #2

那为什么不从TPersistent继承呢？

 

L

lichway

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• 2002-12-05

• #3

up
myaa:=tbb.Create;
//mybb:=tbb.create;
myaa.tindex:=5;
myaa.tstr:='cw'
mybb:=myaa;
或者重载：＝运算符　[^]

 

王

王公子

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• 2002-12-14

• #4

use pointer

 

卡

卡色

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GUEST, unregistred user!

• 2002-12-14

• #5

自己加个assign

 

行

行素

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• 2002-12-14

• #6

重载等号运算符

 

S

stuwei

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GUEST, unregistred user!

• 2002-12-27

• #7

试试mybb^:=myaa^;

 

G

gxcooo

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GUEST, unregistred user!

• 2002-12-27

• #8

重载：＝

 

诸

诸葛白痴

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• 2002-12-28

• #9

加个assign来得方便些，也不难啊

 

Z

zxbyh

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• 2002-12-28

• #10

怎样加？？？？？？？？？？？
给一个Example

 

诸

诸葛白痴

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• 2002-12-28

• #11

看VCL的源代码吧

 

诸

诸葛白痴

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• 2002-12-28

• #12

我看了一下，还是要重载，呵呵，相当于重载运算符，就是将每个属性赋给对方吧，没意义

 

Z

zxbyh

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• 2002-12-28

• #13

BorLand为什么不作一个ObjAssign函数，
这样多好：
Function ObjAssign(SndDestObj:TObject;SndSreObj:TObject):Boolean;

 

Z

zxbyh

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• 2002-12-29

• #14

up

 

B

beckzd

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• 2003-01-03

• #15

study

 

A

aizb

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• 2003-01-03

• #16

unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
tbb=class(TPersistent)
protected
procedure AssignTo(Dest: TPersistent);
Override;
Public
tindex:integer;
tstr:string;
end;
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
myaa:tbb;
mybb:tbb;
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;
implementation
{$R *.dfm}
{ tbb }
procedure tbb.AssignTo(Dest: TPersistent);
begin
if Dest is tbb then
begin
with (Dest as tbb) do
begin
tindex:=Self.tindex;
tstr:=Self.tstr;
end;
end else
inherited;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
myaa:=tbb.Create;
mybb:=tbb.create;
myaa.tindex:=5;
myaa.tstr:='cw';
// mybb:=myaa;
{仅仅复制了指针}
mybb.assign(myaa);{不能执行，因为它们不是从TPersistent继承的}
end;

end.

 

M

mycwcgr_temp

Unregistered / Unconfirmed

GUEST, unregistred user!

• 2003-03-30

• #17

接受答案了.