保存类对象数据 ( 积分: 50 )

unit Znxj;

interface
uses
SysUtils,Classes;
type
TRecord = class
content:string;
XGlink:Tstrings;
public
procedure AddFile(FileName:string);
procedure Addlinks(linkname:Tstrings);
constructor create();overload;
destructor destroy;override;
end;
Frecord= file of Trecord;
DRecord= class
Filedir:string;
znFile:Frecord;
currec:longint;
pos:longint;
num:integer;
public
procedure readrecordtofile(recfile:TRecord);
procedure readrecordout(pos1:longint;Recfile:Trecord);
constructor create(FileDir:string);overload;
destructor destroy;override;
end;
implementation
{ DRecord }
constructor DRecord.create(FileDir: string);
begin
pos:=0;
Filedir:=FileDir;
currec:=0;
if fileexists(FileDir)then
begin
assignfile(znFile,FileDir);
reset(znfile);
end
else
begin
assignfile(znFile,FileDir);
rewrite(znfile);
end;
end;
destructor DRecord.destroy;
begin
inherited;
end;
{ TDGRecord }
procedure DRecord.readrecordout(pos1:longint;Recfile:Trecord);
begin
pos:=pos1;
seek(znfile,pos);
read(znfile,Recfile);
end;
procedure DRecord.readrecordtofile(recfile: TRecord);
begin
seek(znfile,currec);
write(znfile,RecFile);
currec:=currec+1;
end;
{ TRecord }
procedure TRecord.AddFile(FileName: string);
begin
content:=FileName;
end;
procedure TRecord.Addlinks(linkname: tstrings);
begin
XGlink:=linkname;
end;
constructor TRecord.create;
begin
end;
destructor TRecord.destroy;
begin
inherited;
end;
end.


以上是Frecord类保存TRecord类的对象数据。可是实现不了。

TRecord中的数据是变长数据，无法像普通的Record那样利用记录文件进行读写。关于定
长记录的读写，请参考： http://www.delphibbs.com/delphibbs/dispq.asp?lid=010625

如果一定要操作变长数据，那么请参考：
http://www.delphibbs.com/delphibbs/dispq.asp?lid=1768054