base64加解密测试

这是刚刚看到网上的资料，自己做的一个实验。截图：

按钮1是将edit1内容加密，并存入text文件中，按钮2是在text文件中读取加密后的内容，并解密。

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    edt1: TEdit;
    edt2: TEdit;
    edt3: TEdit;
    btn1: TButton;
    btn2: TButton;
    procedure FormCreate(Sender: TObject);
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  t:Text;
  f:string;
  implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
begin
  edt2.Text:=EncodeString(edt1.Text);
  if FileExists(f) then
    begin
      AssignFile(t,f);
    end
    else
    begin
      AssignFile(t,f);
      Rewrite(t);
    end;
    Append(t);
    Writeln(t,edt2.text);
    CloseFile(t);
end;

procedure TForm1.btn2Click(Sender: TObject);
var
s:string;
begin
  if FileExists(f) then
    begin
      AssignFile(t,f);
      Reset(t);
      while not Eof(t) do
        Readln(t,s);
        edt3.Text:=DecodeString(s);
    end;
    CloseFile(t);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  f:=ExtractFilePath(ParamStr(0))+'text.txt';
end;

end.