CRC算法

 

这几天在使用CRC算法生成逐渐编码的时候，发现一个问题，出现了重复的编码值，按道理根据GUID来生成CRC的编码是不会出现重复值的，可就是出现了，我的CRC算法编码如下：

 

    /// <summary>
    /// 人口库主键生成工具类
    /// </summary>
    public class KeysHelper
    {
        static protected UInt64[] crc32Table;
        static protected KeysHelper _crc32 = new KeysHelper();
        private const UInt64 INITIALCRC = 0xFFFFFFFFFFFFFFFFUL;

        KeysHelper()
        {
            const UInt64 ulPolynomial = 0x95AC9329AC4BC9B5UL;
            UInt64 dwCrc;
            crc32Table = new UInt64[256];
            int i, j;
            for (i = 0; i < 256; i++)
            {
                dwCrc = (UInt64)i;
                for (j = 8; j > 0; j--)
                {
                    if ((dwCrc & 1) == 1)
                        dwCrc = (dwCrc >> 1) ^ ulPolynomial;
                    else
                        dwCrc >>= 1;
                }
                crc32Table[i] = dwCrc;
            }
        }

        /// <summary>
        /// 字节数组效验
        /// </summary>
        /// <param name="buffer">ref 字节数组</param>
        /// <returns></returns>
        private static UInt64 ByteCRC(ref byte[] buffer)
        {
            UInt64 ulCRC = INITIALCRC;
            uint len;
            len = (uint)buffer.Length;
            for (uint buffptr = 0; buffptr < len; buffptr++)
            {
                uint tabPtr = (uint)ulCRC & 0xFF;
                tabPtr = tabPtr ^ buffer[buffptr];
                ulCRC = ulCRC >> 8;
                ulCRC = ulCRC ^ crc32Table[tabPtr];
            }
            return ulCRC ^ INITIALCRC;
        }

        /// <summary>
        /// 获取主键编码
        /// </summary>
        /// <param name="sInputString">字符串</param>
        /// <returns></returns>
        public static decimal GetKey(string sInputString)
        {
            if (sInputString != null)
                sInputString = sInputString.ToUpper().Trim();
            byte[] buffer = Encoding.Default.GetBytes(sInputString);
            return (decimal)ByteCRC(ref buffer);
        }

        /// <summary>
        /// 获取主键编码(根据地市来生成)
        /// </summary>
        /// <param name="sInputString">字符串</param>
        /// <param name="areaCode">四位数的编码(4401)</param>
        /// <returns></returns>
        public static decimal GetKey(string sInputString, string areaCode)
        {
            if (sInputString != null)
                sInputString = sInputString.ToUpper().Trim();
            byte[] buffer = Encoding.Default.GetBytes(sInputString);
            decimal val = (decimal)ByteCRC(ref buffer);
            var str = (val.ToString().Length > 14 ? areaCode + val.ToString().Substring(0, 14) : areaCode + val.ToString());
            return decimal.Parse(str);
        }

 

不知道问题出在哪里了，哪位大侠知道的提示一下！

 

我在网上在了一个CRC的算法，我和他的区别就是我只有一个KEY，它有很多个KEY，难道是这个的原因吗？

 

 

using System;

namespace CRC 
...{ 
  public sealed class Crc32 : ICRC 
 ...{ 
  readonly static uint CrcSeed = 0xFFFFFFFF; 
   
  readonly static uint[] CrcTable = new uint[] ...{ 
               0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 
               0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 
               0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 
               0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 
               0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 
               0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 
               0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 
               0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 
               0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 
               0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC, 0x51DE003A, 
               0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 
               0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 
               0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 
               0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 
               0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 
               0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, 
               0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 
               0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 
               0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 
               0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 
               0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 
               0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 
               0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, 0xBE0B1010, 
               0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, 
               0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 
               0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 
               0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 
               0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 
               0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 0xF00F9344, 
               0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 
               0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 
               0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 
               0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 
               0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C, 
               0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 
               0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 
               0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 
               0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 
               0x2CD99E8B, 0x5BDEAE1D, 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 
               0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, 
               0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 
               0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, 
               0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 
               0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 
               0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, 
               0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 
               0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 
               0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 
               0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 
               0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 
               0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 
               0x2D02EF8D 
              }; 
   
  internal static uint ComputeCrc32(uint oldCrc, byte bval) 
  ...{ 
   return (uint)(Crc32.CrcTable[(oldCrc ^ bval) & 0xFF] ^ (oldCrc >> 8)); 
  } 
   
  uint crc = 0; 
   
  public long Value 
  ...{ 
   get 
   ...{ 
    return (long)crc; 
   } 
   set 
   ...{ 
    crc = (uint)value; 
   } 
  } 
   
  public void Reset() 
  ...{ 
   crc = 0; 
  } 
   
  public void Crc(int bval) 
  ...{ 
   crc ^= CrcSeed; 
   crc  = CrcTable[(crc ^ bval) & 0xFF] ^ (crc >> 8); 
   crc ^= CrcSeed; 
  } 
   
  public void Crc(byte[] buffer) 
  ...{ 
   Crc(buffer, 0, buffer.Length); 
  } 
   
  public void Crc(byte[] buf, int off, int len) 
  ...{ 
   if (buf == null) 
   ...{ 
    throw new ArgumentNullException("buf"); 
   } 
    
   if (off < 0 || len < 0 || off + len > buf.Length) 
   ...{ 
    throw new ArgumentOutOfRangeException(); 
   } 
    
   crc ^= CrcSeed; 
    
   while (--len >= 0) 
   ...{ 
    crc = CrcTable[(crc ^ buf[off++]) & 0xFF] ^ (crc >> 8); 
   } 
    
   crc ^= CrcSeed; 
  } 
 } 
} 

 

今晚在试试