68 lines
2.0 KiB
C#
68 lines
2.0 KiB
C#
namespace BLEProtocol
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{
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/// <summary>
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/// CRC16校验计算 (CRC16-CCITT协议)
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/// 多项式: 0x1021, 初始值: 0xFFFF
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/// </summary>
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public static class CRC16
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{
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/// <summary>
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/// 计算CRC16校验值 (CRC16-CCITT)
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/// 使用直接计算法，不使用查找表
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/// </summary>
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/// <param name="data">数据字节数组</param>
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/// <param name="offset">起始偏移</param>
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/// <param name="length">数据长度</param>
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/// <returns>CRC16校验值</returns>
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public static ushort Calculate(byte[] data, int offset, int length)
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{
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ushort crc = 0xFFFF;
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for (int i = 0; i < length; i++)
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{
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crc ^= (ushort)(data[offset + i] << 8);
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for (int j = 0; j < 8; j++)
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{
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if ((crc & 0x8000) != 0)
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{
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crc = (ushort)((crc << 1) ^ 0x1021);
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}
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else
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{
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crc <<= 1;
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}
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}
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}
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return crc;
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}
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/// <summary>
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/// 计算CRC16校验值 (整个数组)
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/// </summary>
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public static ushort Calculate(byte[] data)
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{
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if (data == null || data.Length == 0)
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return 0;
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return Calculate(data, 0, data.Length);
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}
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/// <summary>
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/// 验证CRC16校验
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/// </summary>
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/// <param name="data">数据字节数组(包含CRC)</param>
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/// <param name="length">数据长度(包含CRC的2字节)</param>
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/// <returns>校验是否通过</returns>
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public static bool Validate(byte[] data, int length)
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{
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if (data == null || length < 3)
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return false;
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ushort calculatedCrc = Calculate(data, 0, length - 2);
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ushort receivedCrc = (ushort)(data[length - 2] | (data[length - 1] << 8));
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return calculatedCrc == receivedCrc;
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}
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}
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}
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