unit1.~pas

安全的ACCESS加密方法,比较简单好用

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, DB, Grids, DBGrids, ADODB,Registry;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    ADOTable1: TADOTable;
    DBGrid1: TDBGrid;
    DataSource1: TDataSource;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);


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

var
  Form1: TForm1;

implementation

{$R *.dfm}
const
 titlestr:array[0..15] of byte=
($00,$01,$00,$00,$53,$74,$61,$6E,$64,$61,$72,$64,$20,$4A,$65,$74) ;//对应MDB文件的前16个字节
 titlestr2:array[0..15] of byte=
($48,$4A,$00,$58,$55,$43,$48,$41,$4E,$47,$59,$4F,$55,$00,$20,$20) ;//更改后的MDB文件的前16个字节，自己随便写吧，比如写上自己公司的简称或自已的名
procedure EncrypMDB(filename:string); //用titlestr2内容替换MDB前16个字节，以便实现加密的作用
var F:TFileStream;
begin
   if not fileExists(filename) then  exit;
   F:=TFileStream.create(filename,fmopenwrite);
   try
       F.seek($00,soFromBeginning);
       F.Write(titlestr2,16);
   finally
       F.free;
   end;
end;
procedure uncrypMDB(filename:string); //还原MDB前16个字节
var F:TFileStream;
begin
   if not fileExists(filename) then  exit;
   F:=TFileStream.create(filename,fmopenwrite);
   try
       F.seek($00,soFromBeginning);
       F.Write(titlestr,16);
   finally
       F.free;
   end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
s:string;
begin
EncrypMDB('c:\db1.mm');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
uncrypMDB('c:\db1.mm');
end;

procedure TForm1.Button3Click(Sender: TObject);
var
reg : TRegistry;
begin
reg:=TRegistry.Create;
try
  reg.RootKey:=HKEY_CLASSES_ROOT;
  reg.OpenKey('.ldb',true);
  reg.WriteString(' ','xxyy');
finally
  reg.closekey;
  reg.free;
end;
end;

end.