FreeElementValue Method

Summary

Frees the memory for a value.

Syntax

Objective-C

C++/CLI

Java

public void FreeElementValue( 
   DicomElement element 
)

- (void)freeElementValue:(LTDicomElement *)element;

public void freeElementValue(DicomElement element)

public: 
void FreeElementValue(  
   DicomElement^ element 
)

Parameters

element
An item in the Data Set.

Remarks

Calling this method following a call to one of the DicomDataSet.GetxxxValue, DicomDataSet.GetxxxValuePtr methods, or the GetElementValueCount method will free the memory allocated for the retrieved value. This memory will be freed anyway when the Data Set is freed. Using this method allows you to minimize the memory use in your application.

Example

using Leadtools; 
using Leadtools.Dicom; 
 
 
public void DicomSetGetValueTest() 
{ 
   //Make sure to initialize the DICOM engine, this needs to be done only once  
   //In the whole application 
   DicomEngine.Startup(); 
   using (DicomDataSet dicomDataset = new DicomDataSet()) 
   { 
      dicomDataset.Reset(); 
      dicomDataset.Initialize(DicomClassType.Undefined, DicomDataSetInitializeType.ExplicitVRLittleEndian); 
      DicomElement element = dicomDataset.InsertElement(null, false, DicomTag.CineRate, DicomVRType.IS, false, 0); 
      if (element != null) 
      { 
         dicomDataset.SetIntValue(element, new int[] { 30 }, 1); 
         int[] value = dicomDataset.GetIntValue(element, 0, 1);// can also call GetLongValue 
         Debug.Assert(value[0] == 30); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.ChannelMaximumValue, DicomVRType.OB, false, 0); 
      if (element != null) 
      { 
         dicomDataset.SetByteValue(element, new byte[] { 55 }, 1); 
         byte[] value = dicomDataset.GetByteValue(element, 0, 1); 
         Debug.Assert(value[0] == 55); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.PregnancyStatus, DicomVRType.US, false, 0); 
      if (element != null) 
      { 
         dicomDataset.SetShortValue(element, new short[] { 2 }, 1); 
         short[] value = dicomDataset.GetShortValue(element, 0, 1); 
         Debug.Assert(value[0] == 2); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.SliceLocation, DicomVRType.DS, false, 0); 
      if (element != null) 
      { 
         dicomDataset.SetDoubleValue(element, new double[] { 10.5 }, 1); 
         double[] value = dicomDataset.GetDoubleValue(element, 0, 1); 
         Debug.Assert(value[0] == 10.5); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.PresentationPixelMagnificationRatio, DicomVRType.FL, false, 0); 
      if (element != null) 
      { 
         dicomDataset.SetFloatValue(element, new float[] { 3.2F }, 1); 
         float[] value = dicomDataset.GetFloatValue(element, 0, 1); 
         Debug.Assert(value[0] == 3.2F); 
 
         // Or you can use this overload 
         dicomDataset.SetFloatValue(element, 4.0F); 
         value = dicomDataset.GetFloatValue(element, 0, 1); 
         Debug.Assert(value[0] == 4.0F); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.InstanceCreationDate, DicomVRType.DA, false, 0); 
      if (element != null) 
      { 
         DicomDateValue[] newvalue = new DicomDateValue[1]; 
         newvalue[0].Year = 2004; 
         newvalue[0].Month = 1; 
         newvalue[0].Day = 8; 
         dicomDataset.SetDateValue(element, newvalue); 
         DicomDateValue[] value = dicomDataset.GetDateValue(element, 0, 1); 
         Debug.Assert((value[0].Year == 2004) && (value[0].Month == 1) && (value[0].Day == 8)); 
 
         // Or you can use the SetDateValue overload that takes a single DicomDateValue 
         dicomDataset.SetDateValue(element, new DicomDateValue(1961, 6, 5)); 
         value = dicomDataset.GetDateValue(element, 0, 1); 
         Debug.Assert((value[0].Year == 1961) && (value[0].Month == 6) && (value[0].Day == 5)); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.InstanceCreationTime, DicomVRType.TM, false, 0); 
      if (element != null) 
      { 
         DicomTimeValue[] newvalue = new DicomTimeValue[1]; 
         newvalue[0].Hours = 2; 
         newvalue[0].Minutes = 3; 
         newvalue[0].Seconds = 5; 
         dicomDataset.SetTimeValue(element, newvalue); 
         DicomTimeValue[] value = dicomDataset.GetTimeValue(element, 0, 1); 
         Debug.Assert((value[0].Hours == 2) && (value[0].Minutes == 3) && (value[0].Seconds == 5)); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.AcquisitionDateTime, DicomVRType.DT, false, 0); 
      if (element != null) 
      { 
         DicomDateTimeValue[] newvalue = new DicomDateTimeValue[1]; 
         newvalue[0].Year = 2004; 
         newvalue[0].Month = 1; 
         newvalue[0].Day = 8; 
         newvalue[0].Hours = 2; 
         newvalue[0].Minutes = 3; 
         newvalue[0].Seconds = 5; 
         dicomDataset.SetDateTimeValue(element, newvalue); 
         DicomDateTimeValue[] value = dicomDataset.GetDateTimeValue(element, 0, 1); 
         Debug.Assert((value[0].Hours == 2) && (value[0].Minutes == 3) && (value[0].Seconds == 5)); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.PatientAge, DicomVRType.AS, false, 0); 
      if (element != null) 
      { 
         DicomAgeValue[] newvalue = new DicomAgeValue[1]; 
         newvalue[0].Number = 25; 
         newvalue[0].Reference = DicomAgeReferenceType.Days; 
         dicomDataset.SetAgeValue(element, newvalue); 
         DicomAgeValue[] value = dicomDataset.GetAgeValue(element, 0, 1); 
         Debug.Assert((value[0].Number == 25)); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.PatientName, DicomVRType.PN, false, 0); 
      if (element != null) 
      { 
         dicomDataset.FreeElementValue(element); 
         dicomDataset.SetStringValue(element, "John Doe", DicomCharacterSetType.Default); 
         Debug.Assert(dicomDataset.GetElementValueCount(element) == 1); 
         Debug.Assert(dicomDataset.GetStringValue(element, 0) == "John Doe"); 
      } 
 
      byte[] inPreamble = new byte[128]; 
      for (int i = 0; i < 128; i++) 
      { 
         inPreamble[i] = (byte)i; 
      } 
      dicomDataset.SetPreamble(inPreamble, 0, 128); 
      byte[] outPreamble = dicomDataset.GetPreamble(128); 
 
      // Or you can use this overload which takes an offset 
      dicomDataset.GetPreamble(out outPreamble, 0, 128); 
 
      Debug.Assert(inPreamble.Length == outPreamble.Length); 
 
      element = dicomDataset.FindFirstElement(element, DicomTag.NumberOfRemainingSubOperations, true); 
      if (element != null) 
      { 
         //We don't really need to do this 
         dicomDataset.FreeElementValue(element); 
         byte[] inBinaryValue = new byte[2]; 
         inBinaryValue[0] = 0; 
         inBinaryValue[1] = 1; 
         dicomDataset.SetBinaryValue(element, inBinaryValue, 2); 
         byte[] outBinaryValue = dicomDataset.GetBinaryValue(element, 2); 
         Debug.Assert((outBinaryValue[0] == 0) && (outBinaryValue[1] == 1)); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.StudyDate, DicomVRType.DA, false, 0); 
      if (element != null) 
      { 
         DicomDateValue date1 = new DicomDateValue(); 
         date1.Day = 1; 
         date1.Month = 2; 
         date1.Year = 2005; 
         DicomDateRangeValue[] newvalue = new DicomDateRangeValue[1]; 
         newvalue[0].Date1 = date1; 
         newvalue[0].Type = DicomRangeType.Lower; 
         dicomDataset.SetDateRangeValue(element, newvalue); 
         DicomDateRangeValue value = dicomDataset.GetDateRangeValue(element, 0); 
         Debug.Assert((value.Type == DicomRangeType.Lower) && (value.Date1.Year == 2005)); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.StudyTime, DicomVRType.TM, false, 0); 
      if (element != null) 
      { 
         DicomTimeValue time1 = new DicomTimeValue(); 
         time1.Hours = 2; 
         time1.Minutes = 1; 
         time1.Seconds = 3; 
         DicomTimeRangeValue[] newvalue = new DicomTimeRangeValue[1]; 
         newvalue[0].Time1 = time1; 
         newvalue[0].Type = DicomRangeType.Lower; 
         dicomDataset.SetTimeRangeValue(element, newvalue); 
         DicomTimeRangeValue value = dicomDataset.GetTimeRangeValue(element, 0); 
         Debug.Assert((value.Type == DicomRangeType.Lower) && (value.Time1.Hours == 2)); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.PatientID, DicomVRType.LO, false, 0); 
      if (element != null) 
      { 
         dicomDataset.SetConvertValue(element, "154-4485", 1); 
         Debug.Assert(dicomDataset.GetConvertValue(element) == "154-4485"); 
      } 
 
      element = dicomDataset.InsertElement(null, false, DicomTag.SelectorULValue, DicomVRType.UL, false, 0); 
      if (element != null) 
      { 
         // Set two unsigned integer values (minimum and maximum unsigned 32-bit values) 
         long[] values = new long[] { 0, 4294967295 }; 
         dicomDataset.SetLongValue(element, values, 2); 
 
         string s = dicomDataset.GetConvertValue(element); 
         Debug.Assert(dicomDataset.GetConvertValue(element) == "0\\4294967295"); 
      } 
 
      dicomDataset.Save(Path.Combine(LEAD_VARS.ImagesDir, "Test.dcm"), DicomDataSetSaveFlags.None); 
   } 
   DicomEngine.Shutdown(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}