首先有两个自定的转换函数：  function myStrToHex(s:string):string; //字串转16进制
var    TmpStr:string;    i:integer;
begin    TmpStr:='';    for i:=1 to Length(s)do    TmpStr:=TmpStr+IntToHex(ord(s[i]),2);    Result:=TmpStr;
end;    function myHexToStr(S:string):string; //16进制转字串
var    HexS,TmpStr:string;    i:Integer;    a:Byte;
begin    HexS:=s;    if Length(HexS) mod 2=1 then    HexS:=HexS+'0';    TmpStr:='';    for i:=1 to(Length(HexS)div 2)do    begin    a:=StrToInt('$'+HexS[2*i-1]+HexS[2*i]);    TmpStr:=TmpStr+Chr(a);    end;    Result:=TmpStr;
end;
function myStrToHex(s:string):string; //字串转16进制
var  TmpStr:string;  i:integer;
begin  TmpStr:='';  for i:=1 to Length(s)do  TmpStr:=TmpStr+IntToHex(ord(s[i]),2);  Result:=TmpStr;
end;  function myHexToStr(S:string):string; //16进制转字串
var  HexS,TmpStr:string;  i:Integer;  a:Byte;
begin  HexS:=s;  if Length(HexS) mod 2=1 then  HexS:=HexS+'0';  TmpStr:='';  for i:=1 to(Length(HexS)div 2)do  begin  a:=StrToInt('$'+HexS[2*i-1]+HexS[2*i]);  TmpStr:=TmpStr+Chr(a);  end;  Result:=TmpStr;
end;   然后就是加密、解密函数了：  {两个函数的参数相同，s为要加密、解密的字串；sKey为密匙}
function EncryptStr(const s:string;sKey:string):string; //加密
var    i,j:Integer;    HexS,HexsKey,MidS,TmpStr:string;    a,b,c:byte;
begin    HexS:=myStrToHex(s);    HexsKey:=myStrToHex(sKey);    MidS:=HexS;    for i:=1 to(Length(HexsKey)div 2)do    begin    if i<>1 then MidS:=TmpStr;    TmpStr:=''; //下面要用到TmpStr，所以要清空     for j:=1 to (Length(MidS)div 2)do    begin    a:=StrToInt('$'+midS[2*j-1]+midS[2*j]);    b:=StrToInt('$'+HexsKey[2*i-1]+HexsKey[2*i]);    c:=a xor b;    tmpstr:=TmpStr+myStrToHex(Chr(c));    end;    end;    Result:=TmpStr;
end;    function DecryptStr(const s:string;sKey:string):string; //解密
var    i,j:Integer;    HexS,HexsKey,MidS,TmpStr:string;    a,b,c:Byte;
begin    HexS:=s;    if Length(HexS)mod 2=1 then //检查是否为字符串     begin    ShowMessage('密文错误！');    Exit;    end;    HexsKey:=myStrToHex(sKey);    TmpStr:=HexS;    MidS:=HexS;    for i:=(length(HexsKey) div 2) downto 1 do    begin    if i<>(length(HexsKey) div 2)then    MidS:=TmpStr;    TmpStr:=''; //下面要用到TmpStr，所以要清空     for j:=1 to(length(MidS) div 2)do    begin    a:=StrToInt('$'+MidS[2*j-1]+MidS[2*j]);    b:=StrToInt('$'+HexsKey[2*i-1]+HexsKey[2*i]);    c:=a xor b;    TmpStr := TmpStr+myStrToHex(Chr(c));    end;    end;    Result:=myHexToStr(TmpStr);
end;
{两个函数的参数相同，s为要加密、解密的字串；sKey为密匙}
function EncryptStr(const s:string;sKey:string):string; //加密
var  i,j:Integer;  HexS,HexsKey,MidS,TmpStr:string;  a,b,c:byte;
begin  HexS:=myStrToHex(s);  HexsKey:=myStrToHex(sKey);  MidS:=HexS;  for i:=1 to(Length(HexsKey)div 2)do  begin  if i<>1 then MidS:=TmpStr;  TmpStr:=''; //下面要用到TmpStr，所以要清空  for j:=1 to (Length(MidS)div 2)do  begin  a:=StrToInt('$'+midS[2*j-1]+midS[2*j]);  b:=StrToInt('$'+HexsKey[2*i-1]+HexsKey[2*i]);  c:=a xor b;  tmpstr:=TmpStr+myStrToHex(Chr(c));  end;  end;  Result:=TmpStr;
end;  function DecryptStr(const s:string;sKey:string):string; //解密
var  i,j:Integer;  HexS,HexsKey,MidS,TmpStr:string;  a,b,c:Byte;
begin  HexS:=s;  if Length(HexS)mod 2=1 then //检查是否为字符串  begin  ShowMessage('密文错误！');  Exit;  end;  HexsKey:=myStrToHex(sKey);  TmpStr:=HexS;  MidS:=HexS;  for i:=(length(HexsKey) div 2) downto 1 do  begin  if i<>(length(HexsKey) div 2)then  MidS:=TmpStr;  TmpStr:=''; //下面要用到TmpStr，所以要清空  for j:=1 to(length(MidS) div 2)do  begin  a:=StrToInt('$'+MidS[2*j-1]+MidS[2*j]);  b:=StrToInt('$'+HexsKey[2*i-1]+HexsKey[2*i]);  c:=a xor b;  TmpStr := TmpStr+myStrToHex(Chr(c));  end;  end;  Result:=myHexToStr(TmpStr);
end;   现在已经可以使用了，调用EncryptStr和DecryptStr分别加密、解密  例：  [delphi] view plaincopyprint?Edit1.Text:=EncryptStr('Hello','delphi');    Edit1.Text:=DecryptStr(Edit1.Text,'delphi');
Edit1.Text:=EncryptStr('Hello','delphi');  Edit1.Text:=DecryptStr(Edit1.Text,'delphi');