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EnumerateElements Method

Enumerates the elements (nodes) of this SvgDocument with the specified options.
public void EnumerateElements( 
   SvgEnumerateOptions options, 
   SvgEnumerateElementsCallback callback, 
   object userData 
- (BOOL)enumerateElementsWithOptions:(nullable LTSvgEnumerateOptions *)options userData:(nullable id)userData callback:(BOOL (^)(LTSvgDocument *document, LTSvgNodeHandle *node, id _Nullable userData))callback error:(NSError **)error NS_SWIFT_NAME(enumerateElements(options:userData:callback:)); 
public void enumerateElements(SvgEnumerateOptions options, SvgEnumerateElementsCallback callback, Object userData) 
void EnumerateElements(  
   SvgEnumerateOptions^ options, 
   SvgEnumerateElementsCallback^ callback, 
   Object^ userData 
def EnumerateElements(self,callback,userData): 


Options to use. Can be null.

Callback to receive the elements (nodes). Cannot be null.

Optional user data that will be passed to the callback.


Use this method to enumerate the elements of this SvgDocument using the specified options.

This method will throw an exception if this document is not flat (the value of IsFlat is false) or if it does not have valid physical (pixel) bounds (the value of Bounds.IsValid is false).

If the value of  options is null, then the following default options will be used:

Member Value



This example will use EnumerateElements to extract the embedded images from an SVG file and save them to disk and replace each with a link to the file.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Drawing; 
using Leadtools.Forms.DocumentWriters; 
using Leadtools.Svg; 
using Leadtools.Document.Writer; 
private static void SvgDocumentEnumerateElementsExample() 
   // The source PDF file 
   var sourceFile = $@"{LEAD_VARS.ImagesDir}\Leadtools.pdf"; 
   var beforeSvgFile = $@"{LEAD_VARS.ImagesDir}\Leadtools_before.svg"; 
   var afterSvgFile = $@"{LEAD_VARS.ImagesDir}\Leadtools_after.svg"; 
   // Assume this is our Virtual Directory 
   var virtualDirectory = "http://localhost/leadtools_images/svg/resources"; 
   // Assume this phrysical directory maps to the Virtual Directory 
   var physicalDirectory = $@"{LEAD_VARS.ImagesDir}\svg\resources"; 
   if (!Directory.Exists(physicalDirectory)) 
   // Our SVG element enumartion callback 
   SvgEnumerateElementsCallback callback = (SvgDocument document, SvgNodeHandle node, object userData) => 
      if (node.ElementType == SvgElementType.Image) 
         // Get the href 
         var href = node.GetAttributeValue("xlink:href"); 
         if (!string.IsNullOrEmpty(href)) 
            // Parse it as data URI 
            var dataUri = SvgDataUri.Parse(href); 
            // Check if it is a data URI 
            if (dataUri.IsDataUri) 
               // Yes, create a new file in a virtual directory 
               // Show the dataURI properties 
               Console.WriteLine("Replacing data URI"); 
               Console.WriteLine("Format:" + dataUri.ImageFormat); 
               if (dataUri.MediaLength > 0) 
                  Console.WriteLine("Media:" + dataUri.Href.Substring(dataUri.MediaOffset, dataUri.MediaLength)); 
               if (dataUri.CharSetOffset > 0) 
                  Console.WriteLine("CharSet:" + dataUri.Href.Substring(dataUri.CharSetOffset, dataUri.CharSetLength)); 
                  Console.WriteLine("CharSet: not set"); 
               Console.WriteLine("IsBase64:" + dataUri.IsBase64); 
               Console.WriteLine("ImageFormat:" + dataUri.ImageFormat); 
               var extension = dataUri.Extension; 
               Console.WriteLine("Extension:" + dataUri.Extension); 
               // Get a file name 
               var name = Guid.NewGuid().ToString().Replace("-", "") + "." + dataUri.Extension; 
               // Save it 
               // Full physical path 
               var filePath = Path.Combine(physicalDirectory, name); 
               /* Alternatively you can save the data yourself using this code 
               var data = dataUri.Href.Substring(dataUri.ValueOffset, dataUri.ValueLength); 
               // Save the data 
               var base64String = dataUri.Href.Substring(dataUri.ValueOffset, dataUri.ValueLength); 
               byte[] rawData = Convert.FromBase64String(base64String); 
               // Save it to disk 
               File.WriteAllBytes(filePath, rawData); 
               // Finally replace the attribute in the image element with the URI 
               var virtualPath = virtualDirectory + "/" + name; 
               node.SetAttributeValue("xlink:href", virtualPath); 
               Console.WriteLine("Does not contain a valid data URI."); 
      return true; 
   using (var rasterCodecs = new RasterCodecs()) 
      // Use 300 DPI when loading document images 
      rasterCodecs.Options.RasterizeDocument.Load.Resolution = 300; 
      // Load the first page as SVG 
      using (var svg = rasterCodecs.LoadSvg(sourceFile, 1, null) as SvgDocument) 
         if (!svg.IsFlat) 
         if (!svg.Bounds.IsValid) 
         // Save this SVG to disk, report the size 
         svg.SaveToFile(beforeSvgFile, null); 
         Console.WriteLine("Before unembedding the image, size is " + new FileInfo(beforeSvgFile).Length); 
         // Now enumerate the elements to replace each embedded image with a URL 
         // Since we are going to modify the SVG, call BeginUpdate/EndUpdate to speed up the process 
         svg.EnumerateElements(new SvgEnumerateOptions { EnumerateDirection = SvgEnumerateDirection.TopToBottom }, callback, null); 
         // Save this SVG to disk again, report the size, should be alot smaller since the image are unembedded and stored as external resources 
         svg.SaveToFile(afterSvgFile, null); 
         Console.WriteLine("Before unembedding the image, size is " + new FileInfo(afterSvgFile).Length); 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS22\Resources\Images"; 

Target Platforms

Help Version 22.0.2023.4.20
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Leadtools.Svg Assembly

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© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.