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C#实现CRC8、CRC16、CRC32校验算法

news 2025/9/27 7:03:03

C#实现CRC8、CRC16、CRC32校验算法，包含多种多项式支持和工业级应用优化：

一、CRC校验基础类库实现

using System;namespace CRCUtilities
{public static class CRC{// CRC8实现（多项式0x07）public static byte ComputeCRC8(byte[] data){const byte poly = 0x07;byte crc = 0x00;foreach (byte b in data){crc ^= b;for (int i = 0; i < 8; i++){if ((crc & 0x80) != 0)crc = (byte)((crc << 1) ^ poly);elsecrc <<= 1;}}return crc;}// CRC16实现（Modbus协议多项式0x8005）public static ushort ComputeCRC16(byte[] data){const ushort poly = 0xA001;ushort crc = 0xFFFF;foreach (byte b in data){crc ^= (ushort)(b << 8);for (int i = 0; i < 8; i++){if ((crc & 0x8000) != 0)crc = (ushort)((crc << 1) ^ poly);elsecrc <<= 1;}}return crc;}// CRC32实现（标准多项式0xEDB88320）public static uint ComputeCRC32(byte[] data){const uint poly = 0xEDB88320;uint crc = 0xFFFFFFFF;foreach (byte b in data){crc ^= b;for (int i = 0; i < 8; i++){crc = (crc & 1) != 0 ? (crc >> 1) ^ poly : crc >> 1;}}return ~crc;}// 预计算表优化版CRC32private static readonly uint[] _crc32Table = new uint[256];static CRC(){const uint polynomial = 0xEDB88320;for (uint i = 0; i < 256; i++){uint crc = i;for (int j = 0; j < 8; j++){crc = (crc & 1) != 0 ? (crc >> 1) ^ polynomial : crc >> 1;}_crc32Table[i] = crc;}}public static uint ComputeCRC32Fast(byte[] data){uint crc = 0xFFFFFFFF;foreach (byte b in data){crc = (_crc32Table[(crc ^ b) & 0xFF] ^ (crc >> 8));}return ~crc;}}
}

二、工业级应用示例

1. Modbus通信校验

public class ModbusDevice
{public byte[] ReadHoldingRegisters(ushort address, ushort count){// 构造请求帧byte[] request = new byte[8]{0x01, 0x03, (byte)(address >> 8), (byte)address,0x00, (byte)(count >> 8), (byte)count, 0x00};// 添加CRC校验ushort crc = CRC.ComputeCRC16(request);request = request.Concat(new byte[] { (byte)crc, (byte)(crc >> 8) }).ToArray();// 发送请求并接收响应...}
}

2. 文件完整性校验

public class FileIntegrityChecker
{public static string CalculateFileHash(string filePath){using (var fs = new FileStream(filePath, FileMode.Open, FileAccess.Read)){byte[] buffer = new byte[4096];int bytesRead;using (var md5 = MD5.Create()){while ((bytesRead = fs.Read(buffer, 0, buffer.Length)) > 0){md5.TransformBlock(buffer, 0, bytesRead, buffer, 0);}md5.TransformFinalBlock(buffer, 0, 0);}return BitConverter.ToString(md5.Hash).Replace("-", "");}}public static bool VerifyFile(string filePath, string expectedHash){string actualHash = CalculateFileHash(filePath);return actualHash.Equals(expectedHash, StringComparison.OrdinalIgnoreCase);}
}

三、性能优化

查表法加速（适用于CRC32）：

// 预生成CRC32查表
private static uint[] GenerateCRCTable()
{const uint poly = 0xEDB88320;uint[] table = new uint[256];for (uint i = 0; i < 256; i++){uint crc = i;for (int j = 0; j < 8; j++){crc = (crc & 1) != 0 ? (crc >> 1) ^ poly : crc >> 1;}table[i] = crc;}return table;
}

SIMD优化（需.NET Core 3.0+）：

using System.Runtime.Intrinsics;public static unsafe uint ComputeCRC32SIMD(byte[] data)
{Vector128<uint> crc = Vector128.Create(0xFFFFFFFF);fixed (byte* ptr = data){for (int i = 0; i < data.Length; i += 16){var chunk = Vector128.Load(ptr + i);crc = Vector128.Xor(crc, Vector128.Create((uint)chunk[0]));// SIMD位运算优化...}}return ~crc.ToScalar();
}

参考项目 c# CRC8、CRC16、CRC32校验程序实例 www.youwenfan.com/contentcsi/62497.html

四、测试用例与验证

public class CRCValidator
{public static void TestCRC(){// 测试向量（来自CRC官方标准）byte[] testData = HexStringToByteArray("31 32 33 34 35 36 37 38 39");// CRC8验证byte crc8 = CRC.ComputeCRC8(testData);Console.WriteLine($"CRC8: 0x{crc8:X2}"); // 预期输出: 0x1C// CRC16验证ushort crc16 = CRC.ComputeCRC16(testData);Console.WriteLine($"CRC16: 0x{crc16:X4}"); // 预期输出: 0x29B1// CRC32验证uint crc32 = CRC.ComputeCRC32(testData);Console.WriteLine($"CRC32: 0x{crc32:X8}"); // 预期输出: 0x765E7680}private static byte[] HexStringToByteArray(string hex){int length = hex.Length;byte[] bytes = new byte[length / 2];for (int i = 0; i < length; i += 2){bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);}return bytes;}
}

五、工程应用

协议适配：
- Modbus RTU：使用CRC16（0xA001多项式）
- Modbus ASCII：使用CRC16（0x8005多项式）
- CAN总线：使用CRC8（0x07多项式）

异常处理：

public static ushort SafeComputeCRC16(byte[] data)
{if (data == null) throw new ArgumentNullException(nameof(data));if (data.Length == 0) return 0xFFFF;return CRC.ComputeCRC16(data);
}

性能监控：

using System.Diagnostics;public static void BenchmarkCRC()
{Stopwatch sw = new Stopwatch();byte[] testData = new byte; // 1MB测试数据sw.Start();for (int i = 0; i < 1000; i++)CRC.ComputeCRC32(testData);sw.Stop();Console.WriteLine($"CRC32耗时: {sw.ElapsedMilliseconds}ms");
}

六、扩展功能实现

批量数据处理：

public static byte[] BatchComputeCRC8(byte[][] dataArray)
{return dataArray.Select(data => CRC.ComputeCRC8(data)).ToArray();
}

异步计算：

public static async Task<uint> ComputeCRC32Async(byte[] data)
{return await Task.Run(() => CRC.ComputeCRC32(data));
}

可视化校验工具：

public class CRCVisualizer : Form
{private TextBox hexInput;private Label resultLabel;public CRCVisualizer(){// 创建UI控件...btnCalculate.Click += (s, e) => {byte[] data = HexStringToByteArray(hexInput.Text);resultLabel.Text = $"CRC32: 0x{CRC.ComputeCRC32(data):X8}";};}
}