GetPrevious Method

Summary

Returns the last DicomTag item in the Data Element Tag Table that immediately precedes the specified item.

Syntax

Objective-C

C++/CLI

Java

public DicomTag GetPrevious( 
   DicomTag tag 
)

- (nullable LTDicomTag *)previous:(LTDicomTag *)tag;

public DicomTag getPrevious(DicomTag tag)

public: 
DicomTag^ GetPrevious(  
   DicomTag^ tag 
)

Parameters

tag
An item in the Data Element Tag Table, the item that immediately precedes this item will be returned.

Return Value

DicomTag class that contains an item in the Data Element Tag Table that immediately precedes the item specified by Data Element Tag.

Remarks

The following methods will also help you navigate the Data Element Tag Table:
- GetFirst
- GetLast
- GetNext
To determine the number of entries in the Data Element Tag Table, use GetCount.

Example

using Leadtools; 
using Leadtools.Dicom; 
 
 
public void TestTagTable() 
{ 
 
   //Make sure to initialize the DICOM engine, this needs to be done only once  
   //In the whole application 
   DicomEngine.Startup(); 
 
   //We don't need to call this since the DicomEngine.Startup already does that for us 
   //These calls are for demonstration purposes only 
   DicomTagTable.Instance.Reset(); 
   DicomTagTable.Instance.Default(); 
 
   //We can also call FindByIndex if we know the index of this Tag 
   DicomTag tag = DicomTagTable.Instance.Find(DicomTag.PatientName); 
   DicomTagTable.Instance.Delete(tag); 
 
   DicomTag tag1 = DicomTagTable.Instance.Insert(DicomTag.PatientName, 0xFFFFFFFF, "Patient's Name", DicomVRType.PN, 1, 1, 1); 
 
   Console.WriteLine("Tag Information:"); 
   Console.WriteLine("code is:         {0}", tag1.ToHexString()); 
   Console.WriteLine("VR is :          {0}", tag1.VR); 
   Console.WriteLine("MinVM is :       {0}", tag1.MinVM); 
   Console.WriteLine("MaxVM is :       {0}", tag1.MaxVM); 
   Console.WriteLine("VMDivider is :   {0}", tag1.VMDivider); 
 
   Debug.Assert(DicomTagTable.Instance.Exists(tag1) == true); 
   DicomTagTable.Instance.SetName(tag1, "Patient's Name 1"); 
 
   int count = 0; 
   //If we want to loop through all the Tags in the table we can do this: 
   tag = DicomTagTable.Instance.GetFirst(); 
   while (tag != null) 
   { 
      // We can also access the rest of the properties of DicomTag in here, 
      // such as DicomTagType.Code, DicomTagType.Name, DicomTagType.Mask 
 
      if (tag.Code == DicomTag.PatientName) 
      { 
         Console.WriteLine(tag.Name); 
      } 
      count++; 
      tag = DicomTagTable.Instance.GetNext(tag); 
   } 
   //We can use GetLast and GetPrevious to achieve the same thing 
 
   Debug.Assert(count == DicomTagTable.Instance.GetCount()); 
 
   DicomEngine.Shutdown(); 
}