public override List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
uint temp_idx = 0;
while (idx < data.Length)
{
DCMAbstractType item = null;
try
{
item = syntax.Decode(data, ref idx);
if (item != null && item.gtag == 0x0002)
{
items.Add(item);
temp_idx = idx;
}
else
{
//但要注意最后那条数据元素必须通过修改idx退回到缓冲区
idx = temp_idx;
break;
}
}
catch (Exception e)
{
if (e.GetType() == typeof(NullReferenceException))
{
idx = temp_idx;
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);
//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);
}
/// <summary>
/// 当中调用传输语法类对象从data[idx]开始解码一条数据元素，添加到items, 循环将整个数据集解码，返回items, 同时变化后的idx通过引用(ref)返回。
/// </summary>
public virtual List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
while (idx < data.Length)
{
DCMAbstractType item = null;
item = syntax.Decode(data, ref idx);
items.Add(item);
}
return(items);
}
public override List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
filemete = new DCMFileMeta(new ExplicitVRLittleEndian());
DCMAbstractType uid = filemete.Decode(data, ref idx).Find((DCMAbstractType type) => type.etag == 0x0010 && type.gtag == 0x0002);
string uid1 = uid.GetValue <string>();
TransferSyntax syn = TransferSyntaxs.All[uid1];
Data = new DCMDataSet(syn);
Data.Decode(data, ref idx);
return(items);
}
public override List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
DCMAbstractType item = TransferSyntax.Decode(data, ref idx);
if (item.gtag == 0xfffe && item.etag == 0xe000) //item start
{
uint ulidx = 0;
byte[] val = (byte[])item.value;
base.Decode(val, ref ulidx);
//tudo：修正idx位置
if (item.length == 0xffffffff) //修正idx位置
{
idx -= (uint)(item.length - ulidx);
}
}
return(items);
}
public override List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
while (idx < data.Length)
{
DCMAbstractType item = null;
//此处调用传输语法对象解码一条数据元素
item = TransferSyntax.Decode(data, ref idx);
if (item.gtag == 0x0002)
{
items.Add(item);
}
else
{
idx -= item.length;
idx -= 8;
break;
}
}
return(items);
}
public override List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
while (idx < data.Length)
{
DCMAbstractType metaitem = null;
uint i = idx;//保存原始idx
//此处调用传输语法对象解码一条数据元素
metaitem = syntax.Decode(data, ref idx);
if (metaitem.gtag == 0x0002)//将文件头元素存入容器
{
items.Add(metaitem);
}
else//修改idx退回到缓冲区
{
idx = items[items.Count - 1].idx;
break;
}
}
return(items);
}
/// <summary>
/// SQ必须重写GetValue方法,因为传进来的参数length是由前边的Getlength方法获取的
/// 而SQ可能取值FFFF
/// </summary>
/// <param name="data"></param>
/// <param name="idx"></param>
/// <param name="length">传入长度数值</param>
/// <returns></returns>
public override byte[] GetValue(byte[] data, ref uint idx, uint length)
{
uint offset = idx;
DCMDataSequence sq = new DCMDataSequence(syntax);
while (idx - offset < length)
{
DCMAbstractType item = syntax.Decode(data, ref idx);
if (item.gtag == 0xfffe && item.etag == 0xe0dd)
{
break;
}
else
{
sq[0] = (DCMDataItem)item;
}
}
GCHandle handle = GCHandle.Alloc(sq);
IntPtr ptr = GCHandle.ToIntPtr(handle);
return(BitConverter.GetBytes(ptr.ToInt64()));
}
//DCMDataSet索引成员
public virtual DCMAbstractType this[uint idx]
{
get
{
//拉姆达表达式(匿名函数)比较tag与索引idx是否相等，返回索引结果
DCMAbstractType item = items.Find(elem => (uint)(elem.gtag << 16) + (elem.etag) == idx);
return(item);
}
set
{
DCMAbstractType val = (DCMAbstractType)value;
DCMAbstractType item = items.Find(elem => (uint)(elem.gtag << 16 + (elem.etag)) == idx);
if (item == null) //not exists
{
items.Add(val);
}
else
{
item.length = val.length;
item.value = val.value;
}
}
}
public virtual List <DCMAbstractType> Decode(byte[] data, ref uint idx)
{
while (idx < data.Length)
{
//此处调用传输语法对象解码一条数据元素
//DCMAbstractType item = TransferSyntax.Decode(data, ref idx);
DCMAbstractType item = TransferSyntax.Decode(data, ref idx);
//判断特殊标记
if (item.gtag == 0xfffe && item.etag == 0xe0dd)
{
break;
}
if (item.gtag == 0xfffe && item.etag == 0xe00d)
{
break;
}
if (item.vr == "SQ")
{
DCMDataSequnce sq = new DCMDataSequnce(TransferSyntax);
uint ulidx = 0;
byte[] val = (byte[])item.value;
sq.Decode(val, ref ulidx);
item.value = sq;
//todo：修正idx位置
if (item.length == 0xffffffff) //修正idx位置
{
idx -= (uint)(item.length - ulidx);
}
}
items.Add(item);
}
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;
}
}
