Delphi 5至2010 [英] Delphi 5 to 2010

问题描述

我在Delphi 5和2010中使用了相同的函数（ OneWayEncrypt（edit1.Text））。

为什么结果不同？ （或者如何从Delphi 2010中获得相同的结果？）

I used same function ( OneWayEncrypt(edit1.Text) ) in Delphi 5 and 2010.
Why the results are different? (Or how can I give the same results from Delphi 2010?)

uses Sysutils, Windows, Dialogs, classes;

function OneWayEncrypt(AStr: string): string;
PROCEDURE CalcCRC32 (p:  pointer; ByteCount:  DWORD; VAR CRCvalue:  DWORD);

implementation

const 
  table:  ARRAY[0..255] OF DWORD = 
  (
    //table consts are here
  );

PROCEDURE CalcCRC32(p: pointer; ByteCount: DWORD; VAR CRCvalue: DWORD);
VAR
  i: DWORD;
  q: ^Byte;
BEGIN
  q := p;
  FOR i := 0 TO ByteCount - 1 DO
  BEGIN
    CRCvalue := (CRCvalue SHR 8) XOR table[q^ XOR (CRCvalue AND $000000FF)];
    INC(q);
  END
END;

function OneWayEncrypt(AStr: string): string;
var
  dwCrc: DWORD;
  s: string;
begin
  dwCrc := $FFFFFFFF; 
  s := 'X' + AStr + '7F';
  CalcCRC32(Addr(s[1]), Length(s), dwCrc);
  result := IntToHex(dwCrc, 8);
end;

推荐答案

您知道 string 在D2010中引用Unicode字符串，而在版本<中引用AnsiString。 D2009？

Are you aware that string refers to a Unicode string in D2010, while it refers to AnsiString in versions < D2009? That should be the source of your problem.

因此，您有两种选择：

• 您可以将所有 string 外观替换为 AnsiString 。当然，在没有Unicode支持的情况下，这应能获得与D5相同的结果


• 您可以重构代码。我想这里的黑客指针至关重要。但是我不得不承认，我没有花时间完全理解代码;-)
  （由于255 consts = ISO8859，很可能您的代码无论如何都不能与Unicode一起使用。 ？）

• You could replace all appearances of string with AnsiString. This should give you the same results as in D5, of course without Unicode support
• You could refactor your code. I guess that the pointer-"hacking" is the crucial part here. But I have to admit, I didn't take the time to fully understand the code ;-) (It could very well be that your code can't be used with Unicode anyways, due to the 255 consts = ISO8859?)

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