如何将字符串保存到文件中?(100分)

如何将特定字符串保存到非文本文件中?即该文件用记事本打开时看到的是乱码?
需要时,怎样从该文件识别到原字符串的内容?

加密？或者压缩？

可以以array of byte+TFileStream方式保存

能不能举例一下,把代码贴出来?

机器刚重做，没重D呢，写一下，你试试
var
S:String;
F:TFileStream;
begin
S:='abcdefg';
F:=TFileStream.Create('a.txt',fmOpenWrite or fmCreate);
//先把S加密一下，下面附加密函数：
F.Write(S[1],Length(MyAry));
FreeAndNil(F);
end;


unit Des;

interface

uses
SysUtils;

type
TKeyByte = array[0..5] of Byte;
TDesMode = (dmEncry, dmDecry);

function EncryStr(Str, Key: String): String;
function DecryStr(Str, Key: String): String;
function EncryStrHex(Str, Key: String): String;
function DecryStrHex(StrHex, Key: String): String;

const
BitIP: array[0..63] of Byte = //初始值置IP
(57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7,
56, 48, 40, 32, 24, 16, 8, 0,
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6 );

BitCP: array[0..63] of Byte = //逆初始置IP-1
( 39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25,
32, 0, 40, 8, 48, 16, 56, 24 );

BitExp: array[0..47] of Integer = // 位选择函数E
( 31, 0, 1, 2, 3, 4, 3, 4, 5, 6, 7, 8, 7, 8, 9,10,
11,12,11,12,13,14,15,16,15,16,17,18,19,20,19,20,
21,22,23,24,23,24,25,26,27,28,27,28,29,30,31,0 );

BitPM: array[0..31] of Byte = //置换函数P
( 15, 6,19,20,28,11,27,16, 0,14,22,25, 4,17,30, 9,
1, 7,23,13,31,26, 2, 8,18,12,29, 5,21,10, 3,24 );

sBox: array[0..7] of array[0..63] of Byte = //S盒
( ( 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 ),

( 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 ),

( 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 ),

( 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 ),

( 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 ),

( 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 ),

( 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 ),

( 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 ) );

BitPMC1: array[0..55] of Byte = //选择置换PC-1
( 56, 48, 40, 32, 24, 16, 8,
0, 57, 49, 41, 33, 25, 17,
9, 1, 58, 50, 42, 34, 26,
18, 10, 2, 59, 51, 43, 35,
62, 54, 46, 38, 30, 22, 14,
6, 61, 53, 45, 37, 29, 21,
13, 5, 60, 52, 44, 36, 28,
20, 12, 4, 27, 19, 11, 3 );

BitPMC2: array[0..47] of Byte =//选择置换PC-2
( 13, 16, 10, 23, 0, 4,
2, 27, 14, 5, 20, 9,
22, 18, 11, 3, 25, 7,
15, 6, 26, 19, 12, 1,
40, 51, 30, 36, 46, 54,
29, 39, 50, 44, 32, 47,
43, 48, 38, 55, 33, 52,
45, 41, 49, 35, 28, 31 );

var
subKey: array[0..15] of TKeyByte;

implementation

procedure initPermutation(var inData: array of Byte);
var
newData: array[0..7] of Byte;
i: Integer;
begin
FillChar(newData, 8, 0);
for i := 0 to 63 do
if (inData[BitIP shr 3] and (1 shl (7- (BitIP and $07)))) <> 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 7 do inData := newData;
end;

procedure conversePermutation(var inData: array of Byte);
var
newData: array[0..7] of Byte;
i: Integer;
begin
FillChar(newData, 8, 0);
for i := 0 to 63 do
if (inData[BitCP shr 3] and (1 shl (7-(BitCP and $07)))) <> 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 7 do inData := newData;
end;

procedure expand(inData: array of Byte; var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 6, 0);
for i := 0 to 47 do
if (inData[BitExp shr 3] and (1 shl (7-(BitExp and $07)))) <> 0 then
outData[i shr 3] := outData[i shr 3] or (1 shl (7-(i and $07)));
end;

procedure permutation(var inData: array of Byte);
var
newData: array[0..3] of Byte;
i: Integer;
begin
FillChar(newData, 4, 0);
for i := 0 to 31 do
if (inData[BitPM shr 3] and (1 shl (7-(BitPM and $07)))) <> 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 3 do inData := newData;
end;

function si(s,inByte: Byte): Byte;
var
c: Byte;
begin
c := (inByte and $20) or ((inByte and $1e) shr 1) or
((inByte and $01) shl 4);
Result := (sBox[c] and $0f);
end;

procedure permutationChoose1(inData: array of Byte;
var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 7, 0);
for i := 0 to 55 do
if (inData[BitPMC1 shr 3] and (1 shl (7-(BitPMC1 and $07)))) <> 0 then
outData[i shr 3] := outData[i shr 3] or (1 shl (7-(i and $07)));
end;

procedure permutationChoose2(inData: array of Byte;
var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 6, 0);
for i := 0 to 47 do
if (inData[BitPMC2 shr 3] and (1 shl (7-(BitPMC2 and $07)))) <> 0 then
outData[i shr 3] := outData[i shr 3] or (1 shl (7-(i and $07)));
end;

procedure cycleMove(var inData: array of Byte; bitMove: Byte);
var
i: Integer;
begin
for i := 0 to bitMove - 1 do
begin
inData[0] := (inData[0] shl 1) or (inData[1] shr 7);
inData[1] := (inData[1] shl 1) or (inData[2] shr 7);
inData[2] := (inData[2] shl 1) or (inData[3] shr 7);
inData[3] := (inData[3] shl 1) or ((inData[0] and $10) shr 4);
inData[0] := (inData[0] and $0f);
end;
end;

procedure makeKey(inKey: array of Byte; var outKey: array of TKeyByte);
const
bitDisplace: array[0..15] of Byte =
( 1,1,2,2, 2,2,2,2, 1,2,2,2, 2,2,2,1 );
var
outData56: array[0..6] of Byte;
key28l: array[0..3] of Byte;
key28r: array[0..3] of Byte;
key56o: array[0..6] of Byte;
i: Integer;
begin
permutationChoose1(inKey, outData56);

key28l[0] := outData56[0] shr 4;
key28l[1] := (outData56[0] shl 4) or (outData56[1] shr 4);
key28l[2] := (outData56[1] shl 4) or (outData56[2] shr 4);
key28l[3] := (outData56[2] shl 4) or (outData56[3] shr 4);
key28r[0] := outData56[3] and $0f;
key28r[1] := outData56[4];
key28r[2] := outData56[5];
key28r[3] := outData56[6];

for i := 0 to 15 do
begin
cycleMove(key28l, bitDisplace);
cycleMove(key28r, bitDisplace);
key56o[0] := (key28l[0] shl 4) or (key28l[1] shr 4);
key56o[1] := (key28l[1] shl 4) or (key28l[2] shr 4);
key56o[2] := (key28l[2] shl 4) or (key28l[3] shr 4);
key56o[3] := (key28l[3] shl 4) or (key28r[0]);
key56o[4] := key28r[1];
key56o[5] := key28r[2];
key56o[6] := key28r[3];
permutationChoose2(key56o, outKey);
end;
end;

procedure encry(inData, subKey: array of Byte;
var outData: array of Byte);
var
outBuf: array[0..5] of Byte;
buf: array[0..7] of Byte;
i: Integer;
begin
expand(inData, outBuf);
for i := 0 to 5 do outBuf := outBuf xor subKey;
buf[0] := outBuf[0] shr 2;
buf[1] := ((outBuf[0] and $03) shl 4) or (outBuf[1] shr 4);
buf[2] := ((outBuf[1] and $0f) shl 2) or (outBuf[2] shr 6);
buf[3] := outBuf[2] and $3f;
buf[4] := outBuf[3] shr 2;
buf[5] := ((outBuf[3] and $03) shl 4) or (outBuf[4] shr 4);
buf[6] := ((outBuf[4] and $0f) shl 2) or (outBuf[5] shr 6);
buf[7] := outBuf[5] and $3f;
for i := 0 to 7 do buf := si(i, buf);
for i := 0 to 3 do outBuf := (buf[i*2] shl 4) or buf[i*2+1];
permutation(outBuf);
for i := 0 to 3 do outData := outBuf;
end;

procedure desData(desMode: TDesMode;
inData: array of Byte; var outData: array of Byte);
// inData, outData 都为8Bytes，否则出错
var
i, j: Integer;
temp, buf: array[0..3] of Byte;
begin
for i := 0 to 7 do outData := inData;
initPermutation(outData);
if desMode = dmEncry then
begin
for i := 0 to 15 do
begin
for j := 0 to 3 do temp[j] := outData[j]; //temp = Ln
for j := 0 to 3 do outData[j] := outData[j + 4]; //Ln+1 = Rn
encry(outData, subKey, buf); //Rn ==Kn==> buf
for j := 0 to 3 do outData[j + 4] := temp[j] xor buf[j]; //Rn+1 = Ln^buf
end;

for j := 0 to 3 do temp[j] := outData[j + 4];
for j := 0 to 3 do outData[j + 4] := outData[j];
for j := 0 to 3 do outData[j] := temp[j];
end
else if desMode = dmDecry then
begin
for i := 15 downto 0 do
begin
for j := 0 to 3 do temp[j] := outData[j];
for j := 0 to 3 do outData[j] := outData[j + 4];
encry(outData, subKey, buf);
for j := 0 to 3 do outData[j + 4] := temp[j] xor buf[j];
end;
for j := 0 to 3 do temp[j] := outData[j + 4];
for j := 0 to 3 do outData[j + 4] := outData[j];
for j := 0 to 3 do outData[j] := temp[j];
end;
conversePermutation(outData);
end;

//////////////////////////////////////////////////////////////

function EncryStr(Str, Key: String): String;
var
StrByte, OutByte, KeyByte: array[0..7] of Byte;
StrResult: String;
I, J: Integer;
begin
if (Length(Str) > 0) and (Ord(Str[Length(Str)]) = 0) then
raise Exception.Create('Error: the last char is NULL char.');
if Length(Key) < 8 then
while Length(Key) < 8 do Key := Key + Chr(0);
while Length(Str) mod 8 <> 0 do Str := Str + Chr(0);

for J := 0 to 7 do KeyByte[J] := Ord(Key[J + 1]);
makeKey(keyByte, subKey);

StrResult := '';

for I := 0 to Length(Str) div 8 - 1 do
begin
for J := 0 to 7 do
StrByte[J] := Ord(Str[I * 8 + J + 1]);
desData(dmEncry, StrByte, OutByte);
for J := 0 to 7 do
StrResult := StrResult + Chr(OutByte[J]);
end;

Result := StrResult;
end;

function DecryStr(Str, Key: String): String;
var
StrByte, OutByte, KeyByte: array[0..7] of Byte;
StrResult: String;
I, J: Integer;
begin
if Length(Key) < 8 then
while Length(Key) < 8 do Key := Key + Chr(0);

for J := 0 to 7 do KeyByte[J] := Ord(Key[J + 1]);
makeKey(keyByte, subKey);

StrResult := '';

for I := 0 to Length(Str) div 8 - 1 do
begin
for J := 0 to 7 do StrByte[J] := Ord(Str[I * 8 + J + 1]);
desData(dmDecry, StrByte, OutByte);
for J := 0 to 7 do
StrResult := StrResult + Chr(OutByte[J]);
end;
while (Length(StrResult) > 0) and
(Ord(StrResult[Length(StrResult)]) = 0) do
Delete(StrResult, Length(StrResult), 1);
Result := StrResult;
end;

///////////////////////////////////////////////////////////

function EncryStrHex(Str, Key: String): String;
var
StrResult, TempResult, Temp: String;
I: Integer;
begin
TempResult := EncryStr(Str, Key);
StrResult := '';
for I := 0 to Length(TempResult) - 1 do
begin
Temp := Format('%x', [Ord(TempResult[I + 1])]);
if Length(Temp) = 1 then Temp := '0' + Temp;
StrResult := StrResult + Temp;
end;
Result := StrResult;
end;

function DecryStrHex(StrHex, Key: String): String;
function HexToInt(Hex: String): Integer;
var
I, Res: Integer;
ch: Char;
begin
Res := 0;
for I := 0 to Length(Hex) - 1 do
begin
ch := Hex[I + 1];
if (ch >= '0') and (ch <= '9') then
Res := Res * 16 + Ord(ch) - Ord('0')
else if (ch >= 'A') and (ch <= 'F') then
Res := Res * 16 + Ord(ch) - Ord('A') + 10
else if (ch >= 'a') and (ch <= 'f') then
Res := Res * 16 + Ord(ch) - Ord('a') + 10
else raise Exception.Create('Error: not a Hex String');
end;
Result := Res;
end;

var
Str, Temp: String;
I: Integer;
begin
Str := '';
for I := 0 to Length(StrHex) div 2 - 1 do
begin
Temp := Copy(StrHex, I * 2 + 1, 2);
Str := Str + Chr(HexToInt(Temp));
end;
Result := DecryStr(Str, Key);
end;

//这里的Str表示你要进行加密的字符串，Key表示密钥；
//function EncryStrHex(Str, Key: String): String;

//这里的Str表示你要进行解密的字符串，Key表示密钥；
//function DecryStrHex(StrHex, Key: String): String;

end.

将 字符串 加密一下再保存不就可以了吗

字符串写到流。流在保存就是二进制的。应该没有多少人能够直接看出

//写过程 ---引用刘麻子的.
begin
Mcode:='1234567890';
User:='刘非';
Rcode:='0123456789';
old:=55;
//以上假定内存变量的值
AssignFile(MyFile,'文件名'); //这一步应该是建立关联
if fileExists('文件名') then
Reset(MyFile,1); //建立文件，1的作用是说明每次读写（所谓的）‘记录’大小
else
ReWrite(MyFile,1); //打开并编辑文件。。。

try
BlockWrite(MyFile,Mcode,11);
BlockWrite(MyFile,User,9);
BlockWrite(MyFile,Rcode,11);
Addr:=Pbyte(@old);
BlockWrite(MyFile,Addr,sizeof(integer));
finally
CloseFile(MyFile); //关闭并保存文件
end;
end;


//读过程，类似的。。。。
begin
AssignFile(MyFile,'文件名'); //这一步应该是建立关联
if fileExists('文件名') then
Reset(MyFile,1); //以读的形式打开文件
try
Blockread(MyFile,Mcode,11);
Blockread(MyFile,User,9);
Blockread(MyFile,Rcode,11);
Addr:=Pbyte(@old); //变量地址
Blockread(MyFile,Addr,sizeof(integer));
finally
CloseFile(MyFile); //关闭并保存文件
end;
showmessage(Mcode);
showmessage(User);
showmessage(Rcode);
showmessage(inttostr(old));
end;

to liuchong:
是DES加密函数吧,以前好象看过,
今天我试了一下四个Funtion
function EncryStr(Str, Key: String): String;
function DecryStr(Str, Key: String): String;
function EncryStrHex(Str, Key: String): String;
function DecryStrHex(StrHex, Key: String): String;
发现第二个 Decrystr(Str, Key)函数好象工作不正常,有时可正确得到原字符串内容,有时不能,如原字符串STR='a'时,经Encrystr(str,'123')加密后,用Decrystr()解密后的结果不是原字符'a',不知何故?

to 网中游：
怎样将字符串写到流，并保存到文件，然后读出，我是一点不懂，请贴代码．

Fs:=TFileStream.create('file',fmCreate);
fs.write(S[1],length(s));

使用这两个函数加密、解密，另外两个是这两个调用的，不是让你直接使用的
//这里的Str表示你要进行加密的字符串，Key表示密钥；
//function EncryStrHex(Str, Key: String): String;

//这里的Str表示你要进行解密的字符串，Key表示密钥；
//function DecryStrHex(StrHex, Key: String): String;

to liuchong:
发现你的DES单元好象是有问题的,我在论坛上找了以前的DES,四个函数都没问题.
其实细看就知道,"另外两个是这两个调用的，不是让你直接使用的",本身是错误的.

结束吧.还是不太清楚关于文件内容的读写.

1、对于文件操作，我已经你代码演示
2、对于你说的“经Encrystr(str,'123')加密后,用Decrystr()解密后的结果不是原字符'a',不知何故?”
我已做了测试：
procedure TForm1.btn1Click(Sender: TObject);
begin
Caption:=DecryStr(EncryStr('a','123'),'123')
end;
结果是正确的

ok

多人接受答案了。