public virtual DCMAbstractType Decode(byte[] data, ref uint idx)
{
DCMDataElement element = new DCMDataElement();
//读取TAG
element.gtag = vrdecoder.GetGroupTag(data, ref idx);
element.etag = vrdecoder.GetElementTag(data, ref idx);
//处理SQ
if (element.gtag == 0xfffe && element.etag == 0xe000) //处理SQ的三个特殊标记
{
DCMDataItem sqitem = new DCMDataItem(this);
uint length = vrdecoder.GetUInt(data, ref idx); //不能用GetLength
uint offset = idx;
while (idx - offset < length)
{
DCMAbstractType sqelem = Decode(data, ref idx); //递归
if (length == 0xffffffff && sqelem.gtag == 0xfffe && sqelem.etag == 0xe00d) //条目结束标记
{
break;
}
sqitem.items.Add(sqelem);
}
return(sqitem);
}
else if (element.gtag == 0xfffe && element.etag == 0xe0dd) //序列结束标记
{
element.vr = "UL";
element.length = vrdecoder.GetUInt(data, ref idx); //不能用GetLength
return(element);
}
//查数据字典得到VR,Name,VM
element.vr = vrdecoder.GetVR(data, ref idx);
DicomDictonaryEntry entry = dicomDictionary.GetEntry(element.gtag, element.etag);
if (entry != null)
{
if (element.vr == "")
{
element.vr = entry.Vr;
}
element.name = entry.Keyword;
element.vm = entry.Vm;
}
else if (element.vr == "" && element.etag == 0)
{
element.vr = "US";
}
//根据得到的值表示法构造VR子类对象
element.vrparser = vrfactory.GetVR(element.vr);
//读取值长度
element.length = element.vrparser.GetLength(data, ref idx);
//读取值
element.value = element.vrparser.GetValue(data, ref idx, element.length);
element.idx = idx;
return(element);
}
public override List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
while (idx < data.Length)
{
DCMDataItem item = new DCMDataItem(TransferSyntax);
item.Decode(data, ref idx); //解码一个item，加入items列表
if (item.items.Count > 0)
{
items.Add(item);
}
else
{
break;
}
}
return(items);
}
public virtual DCMAbstractType Decode(byte[] data, ref uint idx)
{
DCMDataElement element = new DCMDataElement();
//读取TAG
element.gtag = vrdecoder.GetGroupTag(data, ref idx);
element.etag = vrdecoder.GetElementTag(data, ref idx);
//这一项仅仅只用于测试容易看出，Reference==0；
string tag = "(" + element.gtag.ToString("X4") + "," + element.etag.ToString("X4") + ")";
if (element.gtag == 0xfffe && element.etag == 0xe000)
{
DCMDataItem sqitem = new DCMDataItem(this);
sqitem.gtag = element.gtag;
sqitem.etag = element.etag;
uint length = vrdecoder.GetUInt32(data, ref idx);
sqitem.length = length;
uint offset = idx;
//idx小于value长度时,不断地调用Decode方法来解锁;
while (idx - offset < length)
{
//递归,不断地解码
//解出Tag不为DataElemt类型时,重复的递归
DCMAbstractType sqelem = Decode(data, ref idx);
if (sqelem.gtag == 0xfffe && sqelem.etag == 0xe00d)
{
break;
}
sqitem[0] = sqelem;
}
return(sqitem);
}
else if (element.gtag == 0xfffe && element.etag == 0xe00d) //序列结束标记
{
element.vr = "UL"; //回归初始状态
element.length = vrdecoder.GetUInt32(data, ref idx);
//不能用GetLength
//且不用解出Value
return(element);
}
else if (element.gtag == 0xfffe && element.etag == 0xe0dd)
{
element.vr = "UL";//回归初始状态
element.length = vrdecoder.GetUInt32(data, ref idx);
//不能用GetLength
//不用解出Value类了;
return(element);
}
//查数据字典得到VR,Name,VM
element.vr = vrdecoder.GetVR(data, ref idx);
//0002系类文件头并没有在DicomDirationay内有定义
DicomDictonaryEntry entry = dictionary.GetEntry(element.gtag, element.etag);
if (entry != null)
{
element.vr = entry.VR;
element.name = entry.Keyword;
element.vm = entry.VM;
}
else if (element.vr == "" && element.etag == 0)
{
element.vr = "US";
}
if (element.vr == "OB or OW")
{
//在上一层找items[DicomTags.BitsAllocated];但是上层对下层是完全不透明的;怎么办
element.vr = "OW";
}
try
{
vrdecoder = vrfactory.GetVR(element.vr);
element.vrparser = vrdecoder;
//读取值长度
element.length = vrdecoder.GetLength(data, ref idx, element.vr);
//读取值
element.value = vrdecoder.GetValue(data, ref idx, element.length);
return(element);
}
catch
{
throw;
}
}
