高分请高手把以下算法用DELPHI写一遍

[flymeng]

void crc16( unsigned char *p,unsigned int len )
{
unsigned int i;
unsigned char da;
unsigned short CRCWORD=0;
for (i=0;i<len;i++)
{
da=(unsigned char)(CRCWORD/256);
CRCWORD<<=8;
CRCWORD^=CRCtbl[da^p[i]];
}
return CRCWORD;
}

我对C不太懂，只了解DELPHI，请把以上代码改成DELPHI的。

[imho888]

帮顶,网上CRC16的delphi代码多呢,随便找找就一堆

[chenjun_0312]

同意

[sanguomi]

[Quote=引用 1 楼 supertitan001 的回复:]
你的函数不知道哪里copy的，应该是有问题的
首先这是个带返回的函数，不应该是void;
其次，这句 CRCWORD^=CRCtbl[da^p[i]]; 也貌似少了运算符

PS:其实网上到处都是crc16的函数源码，自己找一个吧

[/Quote]
CRCWORD ^= CRCtbl[da^p[i]]; 这句没问题的

[sanguomi]

返回值那里肯定错了

[SuperTitan001]

[Quote=引用 6 楼 sanguomi 的回复:]
引用 1 楼 supertitan001 的回复:
你的函数不知道哪里copy的，应该是有问题的
首先这是个带返回的函数，不应该是void;
其次，这句 CRCWORD^=CRCtbl[da^p[i]]; 也貌似少了运算符

PS:其实网上到处都是crc16的函数源码，自己找一个吧


CRCWORD ^= CRCtbl[da^p[i]]; 这句没问题的

[/Quote]

呵呵，谢谢三国
习惯了pascal，晕了

[sonages]

大致可以这样翻译，你可以试试看：
function crc16(p: PChar; len: Integer): Integer;
var
i: Integer;
da: Integer;
CRCWORD: Integer;
begin
CRCWORD := 0;
for i := 0 to (len - 1) do
begin
da := (CRCWORD shr 8) and $ff;
CRCWORD := CRCWORD shl 8;
CRCWORD := CRCWORD xor CRCtbl[da xor p[i]];
end;

Result := CRCWORD;
end;

[SuperTitan001]

你的函数不知道哪里copy的，应该是有问题的
首先这是个带返回的函数，不应该是void;
其次，这句 CRCWORD^=CRCtbl[da^p[i]]; 也貌似少了运算符

PS:其实网上到处都是crc16的函数源码，自己找一个吧

[fjtxwd]

老帖子
http://topic.csdn.net/u/20081126/10/4489cadb-c08d-4f6f-8784-865d2a8f0315.html

[swetter_hundsun]

帮顶

[flymeng]

不好意思新手，C的程序应该是这样的：
unsigned short crc16( unsigned char *p,unsigned int len )
{
unsigned int i;
unsigned char da;
unsigned short CRCWORD=0;
for (i=0;i<len;i++)
{
da=(unsigned char)(CRCWORD/256);
CRCWORD<<=8;
CRCWORD^=CRCtbl[da^p[i]];
}
return CRCWORD;
}

unsigned short CRCtbl[256] = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0} ;
把以上代码改成delphi的

[flymeng]

这样写对不对？
function gen_crc(const Buffer: array of Byte; const BufferLength: Smallint): Word;
var
c, treat, bcrc: Byte;
wcrc: Word;
i, j: Smallint;
begin
wcrc := 0;
i := 0;
while i < BufferLength do
begin
c := Buffer[i];
for j := 0 to 7 do
begin
treat := c and $80;
c := c shl 1;
bcrc := (wcrc shr 8) and $80;
wcrc := wcrc shl 1;
if treat <> bcrc then
wcrc := wcrc xor $1021;
end;
i := i + 1;
end;
gen_crc := wcrc;
end;