public string Decode(ref string pureURI)
{
if (code == null)
{
return(null);
}
long header = code.SubBitToInteger(0, 8);
var queryTagScheme = xDocCodingTable.Descendants("TagScheme")
.Where(item => item.Element("Header").Value == header.ToString())
.FirstOrDefault();
if (queryTagScheme == null)
{
return("首部值不存在");
}
StringBuilder result = new StringBuilder();
int index = 8;
foreach (var segment in queryTagScheme.Elements())
{
if (segment.Name.ToString() == "Header")//首部
{
result.Append(queryTagScheme.Parent.Attribute("uri").Value);
TagScheme = queryTagScheme.Attribute("name").Value;
}
else if (segment.Name.ToString() == "Filter")//过滤值
{
int len = int.Parse(queryTagScheme.Element("Filter")
.Attribute("len").Value);
long filter = code.SubBitToInteger(index, len);
if (filter == -1)
{
return("过滤值解码错误");
}
index += len;
Filter = (int)filter;
}
else if (segment.Name.ToString() == "Partition")
{ //首先查找分区表名称
string partitionName = segment.Attribute("tableName").Value;
//找到相应的分区表
var queryPartition = xDocPartitionTable.Descendants("Partition")
.Where(item => item.Attribute("name").Value == partitionName);
//首先获取分区值
long partVal = code.SubBitToInteger(index, 3);
if (partVal == -1)
{
return("分区值解码错误");
}
index += 3;
//查找匹配分区表行
var row = queryPartition.Descendants("Row")
.Where(item => item.Attribute("value").Value == partVal.ToString())
.Select(item => new
{
part1BitLen = item.Attribute("col1").Value,
part1Len = item.Attribute("col2").Value,
part2BitLen = item.Attribute("col3").Value,
part2Len = item.Attribute("col4").Value
}).FirstOrDefault();
//解码分区表第一部分
string part1Name = queryPartition.Attributes("part1Name").FirstOrDefault().Value;
string part1Method = queryPartition.Attributes("col2Method").FirstOrDefault().Value;
int len = int.Parse(row.part1BitLen);
int part1Len = int.Parse(row.part1Len);
string part1 = DecodeSegment(index, len, part1Len, part1Method);
if (part1 == null)
{
return(part1Name + "段解码失败");
}
index += len;
result.Append(part1);
//解码分区表第二部分
string part2Name = queryPartition.Attributes("part2Name").FirstOrDefault().Value;
string part2Method = queryPartition.Attributes("col4Method").FirstOrDefault().Value;
len = int.Parse(row.part2BitLen);
int part2Len = int.Parse(row.part2Len);
string part2 = DecodeSegment(index, len, part2Len, part2Method);
if (part2 == null)
{
return(part2Name + "段解码失败");
}
if (part2Method == "Set39_max")
{
index += Symbols.CalcActualLength(part2) * 6 + 6;
}
else
{
index += len;
}
result.Append('.');
result.Append(part2);
}
else //其它逻辑段的解码
{
int len = int.Parse(segment.Attribute("len").Value);
string method = segment.Attribute("method").Value;
string name = segment.Attribute("name").Value;
string other = DecodeSegment(index, len, -1, method);
if (other == null)
{
return("逻辑段：" + name + "解码错误");
}
if (method == "Set39_max")
{
index += Symbols.CalcActualLength(other) * 6 + 6;
}
else
{
index += len;
}
if (other == "")
{
continue;
}
result.Append('.');
result.Append(other);
}
}
pureURI = result.ToString();
return(null);
}
