public void Test1()
{
var buffer = new byte[] { 0x00, 0x1E, 0x01, 0x1A, 0x00, 0x00, 0x01, 0x01 };
var actual = CrcTool.CaculateCCITT16(buffer, 0, buffer.Length);
Assert.AreEqual(0x1089, actual);
}
/// <summary>
/// 解析指定的字节流。
/// </summary>
public void ParseBytes(byte[] bytes)
{
if (bytes == null || bytes.Length < AleFrame.HeadLength)
{
throw new AleFrameParsingException("无法将指定的字节流解析为AleFrame，长度不够。");
}
int startIndex = 0;
// 包长度
var pktLen = RsspEncoding.ToHostUInt16(bytes, startIndex);
startIndex += AleFrame.SizeofHeadLen;
// 版本
this.Version = bytes[startIndex++];
// 应用类型
this.ApplicationType = bytes[startIndex++];
// 传输序列号
this.SequenceNo = RsspEncoding.ToHostUInt16(bytes, startIndex);
startIndex += 2;
// N/R标志
this.IsNormal = (bytes[startIndex++] == 1);
// 包类型
this.FrameType = (AleFrameType)bytes[startIndex++];
// 校验和
if (this.FrameType != AleFrameType.KAA && this.FrameType != AleFrameType.KANA) // 生命信息不需要校验
{
//var actualCrcValue = BitConverter.ToUInt16(bytes, startIndex);
var actualCrcValue = RsspEncoding.ToHostUInt16(bytes, startIndex);
var expectedCrcValue = CrcTool.CaculateCCITT16(bytes, 0, 8);
if (actualCrcValue != expectedCrcValue)
{
throw new AleFrameParsingException(string.Format("解析Ale协议帧时发生异常，CRC检验不一致，期望值是{0}，实际值是{1}。",
expectedCrcValue, actualCrcValue));
}
}
startIndex += 2;
// 用户数据
var userDataLen = pktLen - (AleFrame.HeadLength - AleFrame.SizeofHeadLen);
if (userDataLen < 0)
{
throw new AleFrameParsingException(string.Format("将字节流解析为ALE帧时发生异常，用户数据长度为负值{0}。", userDataLen));
}
this.UserData = AleUserData.Parse(this.FrameType, bytes, startIndex, startIndex + userDataLen - 1);
}
/// <summary>
/// 获取序列化后的字节流。
/// </summary>
public byte[] GetBytes()
{
var bytes = new byte[AleFrame.HeadLength + this.UserDataLength];
var startIndex = 0;
// 包长度
var tempBuf = RsspEncoding.ToNetUInt16(this.PacketLength);
Array.Copy(tempBuf, 0, bytes, startIndex, tempBuf.Length);
startIndex += AleFrame.SizeofHeadLen;
// 版本
bytes[startIndex++] = this.Version;
// 应用类型
bytes[startIndex++] = this.ApplicationType;
// 传输序列号
tempBuf = RsspEncoding.ToNetUInt16(this.SequenceNo);
Array.Copy(tempBuf, 0, bytes, startIndex, tempBuf.Length);
startIndex += 2;
// N/R标志
bytes[startIndex++] = (byte)(this.IsNormal ? 1 : 0);
// 包类型
bytes[startIndex++] = (byte)this.FrameType;
// 校验和
var crcValue = CrcTool.CaculateCCITT16(bytes, 0, 8);
//tempBuf = BitConverter.GetBytes(crcValue);
tempBuf = RsspEncoding.ToNetUInt16(crcValue);
Array.Copy(tempBuf, 0, bytes, startIndex, tempBuf.Length);
startIndex += 2;
// 用户数据
var userData = this.UserData.GetBytes();
if (userData != null)
{
Array.Copy(userData, 0, bytes, startIndex, this.UserDataLength);
}
return(bytes);
}