FindSignature Method

Summary

Returns the Digital Signatures Sequence Item that corresponds to the Digital Signature that has the specified Digital Signature UID, if found in the Data Set.

Syntax

C++

public DicomElement FindSignature( 
   string signatureUID 
)

Public Function FindSignature( _ 
   ByVal signatureUID As String _ 
) As DicomElement

public: 
DicomElement^ FindSignature(  
   String^ signatureUID 
)

Parameters

signatureUID
Character string that contains the Digital Signature UID of the Digital Signature for which to search.

Return Value

The Digital Signatures Sequence Item that corresponds to the Digital Signature with the specified Digital Signature UID, or a null reference (Nothing in VB) if no such Digital Signature was found in the Data Set.

Remarks

Each Digital Signature should be uniquely identified by a UID specified by the Digital Signature UID (0400,0100) under the corresponding Digital Signatures Sequence Item. Call this method to search the whole Data Set for a Digital Signature by its Digital Signature UID. Once the Digital Signatures Sequence Item is obtained, the following methods can be used to verify, delete, or get information about the Digital Signature:

GetSignedElementsCount

Call the GetSignaturesCount and GetSignature methods to enumerate the Digital Signatures in the main Data Set or in an item of a Sequence of Items.

Example

This example will locate (find) a digital signature inside a DICOM dataset by searching for its UID.

using Leadtools; 
using Leadtools.Dicom; 
 
 
public void FindSignature() 
{ 
   string dicomFileName = Path.Combine(LEAD_VARS.ImagesDir, "DICOM", "image3.dcm"); 
   //Make sure to initialize the DICOM engine, this needs to be done only once  
   //In the whole application 
   DicomEngine.Startup(); 
   using (DicomDataSet ds = new DicomDataSet()) 
   { 
      //Load DICOM File 
      ds.Load(dicomFileName, DicomDataSetLoadFlags.None); 
      string signatureUID = "1.2.840.114257.0.130573664"; 
      // Search the whole Data Set for the Digital Signature with the 
      // specified Digital Signature UID 
      DicomElement signatureItem = ds.FindSignature(signatureUID); 
      if (signatureItem != null) 
      { 
         ds.DeleteSignature(signatureItem); 
         Console.WriteLine("Sample: The Digital Signature was found and got deleted."); 
      } 
      else 
      { 
         Assert.Fail("signatureItem is null"); 
         Console.WriteLine("Sample: The Digital Signature could not be found."); 
      } 
   } 
   DicomEngine.Shutdown(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 
}

Imports Leadtools 
Imports Leadtools.Dicom 
 
Public Sub FindSignature() 
   Dim dicomFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "IMAGE3.dcm") 
   'Make sure to initialize the DICOM engine, this needs to be done only once  
   'In the whole application 
   DicomEngine.Startup() 
 
   Dim ds As DicomDataSet = New DicomDataSet() 
   Using (ds) 
 
      'Load DICOM File 
      ds.Load(dicomFileName, DicomDataSetLoadFlags.None) 
      Dim signatureUID As String = "1.2.840.114257.0.130573664" 
      ' Search the whole Data Set for the Digital Signature with the 
      ' specified Digital Signature UID 
      Dim signatureItem As DicomElement = ds.FindSignature(signatureUID) 
      If Not signatureItem Is Nothing Then 
         ds.DeleteSignature(signatureItem) 
         MessageBox.Show("The Digital Signature was found and got deleted.", "Sample") 
      Else 
         MessageBox.Show("The Digital Signature could not be found.", "Sample") 
      End If 
   End Using 
 
   DicomEngine.Shutdown() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const ImagesDir As String = "C:\LEADTOOLS21\Resources\Images" 
End Class