c# CRC16/DNP校验

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c# CRC16/DNP校验

网上找了好多都是crc16/modbus啥的，还有各种查表法、长表、短表、直接计算但是都没找到直接拿过来用的CRC16/DNP校验。要不就是用了以后发现结果根本不对。
最后东拼西凑出来一套成型的东西，结果也都经过校验可以直接用。
这次项目的校验用途呢就是取string然后校验string，当然直接byte会更省事其中步骤也会简单一些，这里还是通过string举例。

 private void button64_Click_1(object sender, EventArgs e){string CRCCheckData = "05 64 05 00 b0 0c 5a 00";//将数据中的空格去掉后调用crc16DNPCheck方法string StringOut=crc16DNPCheck(CRCCheckData.Replace(" ",""));MessageBox.Show(StringOut);}

 public string crc16DNPCheck(string crcdata) {string crcChecked = "";CRC16DNP crc16DNP = new CRC16DNP();//传进来的string转成bytebyte[] byteArray = Enumerable.Range(0, crcdata.Length).Where(x => x % 2 == 0) // 每两个字符为一组.Select(x => Convert.ToByte(crcdata.Substring(x, 2), 16)).ToArray();ushort checksum = crc16DNP.ComputeChecksum(byteArray);//校验结果高低位互换crcChecked = checksum.ToString("X4").Substring(2, 2)+ 		checksum.ToString("X4").Substring(0,2);return crcChecked;}

 public class CRC16DNP{const ushort polynomial = 0xA6BC;  ushort[] table = new ushort[256];public ushort ComputeChecksum(byte[] bytes){ushort crc = 0;for (int i = 0; i < bytes.Length; ++i){byte index = (byte)(crc ^ bytes[i]);crc = (ushort)((crc >> 8) ^ table[index]);}crc = SwapBytes((ushort)(crc ^ 0xffff));return crc;}public byte[] ComputeChecksumBytes(byte[] bytes){ushort crc = ComputeChecksum(bytes);return BitConverter.GetBytes(crc);}private ushort SwapBytes(ushort x){return (ushort)((ushort)((x & 0xff) << 8) | ((x >> 8) & 0xff));}public CRC16DNP(){ushort value;ushort temp;for (ushort i = 0; i < table.Length; ++i){value = 0;temp = i;for (byte j = 0; j < 8; ++j){if (((value ^ temp) & 0x0001) != 0){value = (ushort)((value >> 1) ^ polynomial);}else{value >>= 1;}temp >>= 1;}table[i] = value;}}}