/// <summary>
/// 二进制数据 转成 内容包数据
/// </summary>
/// <param name="data"></param>
/// <returns></returns>
public JT808_PackageData Bytes2PackageData(byte[] data)
{
JT808_PackageData ret = new JT808_PackageData();
// 1. 16byte 或 12byte 消息头
JT808_PackageData.MsgHeader msgHeader = this.ParseMsgHeaderFromBytes(data);
ret.msgHeader = msgHeader;
int msgBodyByteStartIndex = 12 + 1;
// 2. 消息体
// 有子包信息,消息体起始字节后移四个字节:消息包总数(word(16))+包序号(word(16))
if (msgHeader.hasSubPackage)
{
msgBodyByteStartIndex = 16 + 1;
}
byte[] tmp = new byte[msgHeader.msgBodyLength];
Buffer.BlockCopy(data, msgBodyByteStartIndex, tmp, 0, tmp.Length);
ret.setMsgBodyBytes(tmp);
// 3. 去掉分隔符之后，最后一位就是校验码
int checkSumInPkg = data[data.Length - 1 - 1];
int calculatedCheckSum = ExplainUtils.getCheckSum4JT808(data, 0 + 1, data.Length - 1 - 1);
ret.checkSum = (checkSumInPkg);
if (checkSumInPkg != calculatedCheckSum)
{
ret.errorlog = ret.errorlog + "检验码不一致;";// string.Format("检验码不一致,msgid:{},pkg:{},calculated:{}", msgHeader.getMsgId(), checkSumInPkg, calculatedCheckSum);
}
return(ret);
}
/// <summary>
/// 解析生成 消息头
/// </summary>
/// <param name="data"></param>
/// <returns></returns>
private JT808_PackageData.MsgHeader ParseMsgHeaderFromBytes(byte[] bytes)
{
JT808_PackageData.MsgHeader msgHeader = new JT808_PackageData.MsgHeader();
// 1. 消息ID word(16)
msgHeader.msgId = ExplainUtils.ParseIntFromBytes(bytes, 1, 2);
// 2. 消息体属性 word(16)
int msgBodyProps = ExplainUtils.ParseIntFromBytes(bytes, 2 + 1, 2);
msgHeader.msgBodyPropsField = (msgBodyProps);
// [ 0-9 ] 0000,0011,1111,1111(3FF)(消息体长度)
msgHeader.msgBodyLength = (msgBodyProps & 0x3ff);
// [10-12] 0001,1100,0000,0000(1C00)(加密类型)
msgHeader.encryptionType = ((msgBodyProps & 0x1c00) >> 10);
// [ 13_ ] 0010,0000,0000,0000(2000)(是否有子包)
msgHeader.hasSubPackage = (((msgBodyProps & 0x2000) >> 13) == 1);
// [14-15] 1100,0000,0000,0000(C000)(保留位)
msgHeader.reservedBit = (((msgBodyProps & 0xc000) >> 14) + "");
// 3. 终端手机号 bcd[6]
msgHeader.terminalPhone = (ExplainUtils.ParseBcdStringFromBytes(bytes, 4 + 1, 6));
// 4. 消息流水号 word(16) 按发送顺序从 0 开始循环累加
msgHeader.flowId = ExplainUtils.ParseIntFromBytes(bytes, 10 + 1, 2);
// 5. 消息包封装项
// 有子包信息
if (msgHeader.hasSubPackage)
{
// 消息包封装项字段
msgHeader.packageInfoField = ExplainUtils.ParseIntFromBytes(bytes, 12 + 1, 4);
msgHeader.totalSubPackage = ExplainUtils.ParseIntFromBytes(bytes, 12 + 1, 2);
msgHeader.subPackageSeq = ExplainUtils.ParseIntFromBytes(bytes, 12 + 1, 2);
}
return(msgHeader);
}
