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LoadJsonBeforeElementCallback Delegate

Summary

Optional delegate method that is used with the LoadJson methods.

Syntax

C++/CLI

public delegate bool LoadJsonBeforeElementCallback( 
   LoadJsonBeforeElementData data 
)

public delegate bool LoadJsonBeforeElementCallback(  
   LoadJsonBeforeElementData^ data 
)

Parameters

data
An instance of the LoadJsonBeforeElementData class containing the progress callback data.

Return Value

true to include this DICOM element in the DicomDataSet; false to exclude the element from the DicomDataSet

Remarks

This delegate is called once for each DICOM element, before the element is added to the DicomDataSet. If you pass this delegate with the LoadJson methods, you must fill in certain fields of the data For details, see the documentation for LoadJsonBeforeElementData

Example

This example will load a sample DICOM data set, then save it as an JSON file (with no binary data), and then reload the JSON file into a DicomDataSet object. The LoadJsonBeforeElementCallback callback is used to change the patient name, remove the patient birthdate, and display which elements have children.

using Leadtools.Dicom; 
using Leadtools.Dicom.Common; 
using Leadtools.Dicom.Common.Extensions; 
using Leadtools; 
using Leadtools.Dicom.Common.Linq.BasicDirectory; 
using Leadtools.Dicom.Common.DataTypes; 
 
using Leadtools.Codecs; 
 
public void LoadJsonCallbackExample() 
{ 
   string dicomFileNameIn = Path.Combine(LEAD_VARS.ImagesDir,"DICOM", "image2.dcm"); 
   string jsonFileNameOut = Path.Combine(LEAD_VARS.ImagesDir, "test.json"); 
   string dicomFileNameOut = Path.Combine(LEAD_VARS.ImagesDir, "test.dcm"); 
 
   // Initialize DICOM engine 
   DicomEngine.Startup(); 
 
   DicomDataSet ds = new DicomDataSet(); 
 
   // Load an existing DICOM file 
   ds.Load(dicomFileNameIn, DicomDataSetLoadFlags.None); 
 
   // Save as JSON to a file with no binary data 
   // For the demo, keep the json output file size small by skipping the pixel data 
   // Use the SaveJsonCallback delegate to customize the json file 
   DicomDataSetSaveJsonFlags jsonFlags = 
      DicomDataSetSaveJsonFlags.IgnoreBinaryData | 
      DicomDataSetSaveJsonFlags.TrimWhiteSpace; 
 
   ds.SaveJson(jsonFileNameOut, jsonFlags); 
 
   // Use a LoadmlCallback to read the customized json file 
   ds.LoadJson(jsonFileNameOut, DicomDataSetLoadJsonFlags.None, MyLoadJsonBeforeElementCallback, MyLoadJsonAfterElementCallback); 
 
   // Save the result -- there will be no pixel data 
   ds.Save(dicomFileNameOut, DicomDataSetSaveFlags.None); 
 
   DicomEngine.Shutdown(); 
} 
 
private static bool MyLoadJsonBeforeElementCallback(LoadJsonBeforeElementData data) 
{ 
   // Remove Patient Birth Date 
   if (data.Tag == DicomTag.PatientBirthDate) 
   { 
      return false; 
   } 
 
   // Change the patient name 
   if (data.Tag == DicomTag.PatientName) 
   { 
      data.ElementValue = "NewLast^NewFirst"; 
   } 
 
   // Write the elements to the consolee that have child elements 
   if (data.HasChildElements) 
   { 
      Console.WriteLine("Element {0} has child elements.", data.Tag); 
   } 
   return true; 
} 
 
private static void MyLoadJsonAfterElementCallback(LoadJsonAfterElementData data) 
{ 
   if (data.DicomElement.Tag == DicomTag.PixelData) 
   { 
      // here you could call one of the following to set the pixel data 
      //    data.DicomDataSet.SetBinaryValue  
      //    data.DicomDataSet.SetImage() 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}