unit1.~pas

用DELPHI实现的 ISBN 和图书编码的转换算法.速度比较快

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    Edit2: TEdit;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    function CodeToIsbn(isbn:string):string;
    function IsbnToCode(Code:string):string;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function TForm1.CodeToIsbn(isbn: string): string;
var
  count:word;
  i:byte;
begin
  count:=0;
  isbn:=AnsiReplaceStr(isbn,'-','');
  for I:=10 downto 2 do
    count:=count+i*strtoint(isbn[14-i]);
  i:=count mod 11;
  result:=copy(isbn,4,9);
  case i of
  0: result:=result+inttostr(0);
  10: result:=result+'x';
  else result:=result+inttostr(11-i);
  end;
end;

function TForm1.IsbnToCode(Code: string): string;
var
  count1,count2:word;
  i:byte;
begin
  count1:=0;
  count2:=0;
  result:='978'+Copy(AnsiReplaceStr(code,'-',''),1,9);
  for i:=1 to 12 do
  begin
    if (i mod 2)=0 then
      count2:=count2+strtoint(Result[i])
    else
      count1:=count1+strtoint(Result[i]);
  end;
  count1:=count1+count2*3;
  i:=(10-(count1 mod 10)) mod 10;//因为i有可能为10，因此还要取各位数
  result:=result+inttostr(i);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  edit2.Text:=CodeToIsbn(edit1.Text);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  edit1.Text:=IsbnToCode(edit2.Text);
end;

end.