How to flatten the annotation on a specific layer from an existing PDF?

The Syncfusion Essential PDF is a feature rich and high-performance .NET PDF library used to create, read, and edit PDF documents programmatically without Adobe dependencies. This library also offers functionality to merge, split, stamp, forms, compress, and secure PDF files.

Using this library, you can flatten the annotation on a specific layer from an existing PDF in C# and VB.NET. This application uses the following annotation for flattening.

Steps to flatten the annotation on a specific layer form existing PDF programmatically in C#:

1. Create a new C# console application project.

2. Install the Syncfusion.Pdf.WinForms NuGet package as a reference to your .NET Framework application from NuGet.org.

   

3. Include the following code snippet in main method of Program.cs file to flatten the annotation on a specific layer.

   C#

   //Load the existing PDF document
   PdfLoadedDocument loadedDocument = new PdfLoadedDocument("Sample.pdf");
   //Get all the pages
   foreach (PdfLoadedPage loadedPage in loadedDocument.Pages)
   {
      //Flatten all the annotations in the page
      foreach (PdfLoadedAnnotation annotation in loadedPage.Annotations)
      {
          //Check for the circle annotation
          if (annotation is PdfLoadedCircleAnnotation)
          {
              //Flatten the circle annotation
              annotation.Flatten = true;
              //remove annotation layer from loadedDocument
              loadedDocument.Layers.Remove(annotation.Layer);        
          }           
       }
   }
   //Save and close the PDF document instance
   loadedDocument.Save("FlattenOutput.pdf");
   loadedDocument.Close(true);
   

   VB.NET

      'Load the existing PDF document
      Dim loadedDocument As New PdfLoadedDocument("Sample.pdf")
      'Get all the pages
     For Each loadedPage As PdfLoadedPage In loadedDocument.Pages
      ' Flatten all the annotations in the page
      For Each annotation As PdfLoadedAnnotation In loadedPage.Annotations
          ' Check for the circle annotation
          If TypeOf annotation Is PdfLoadedCircleAnnotation Then
              ' Flatten the circle annotation
              annotation.Flatten = True
              ' Remove annotation layer from loadedDocument
              loadedDocument.Layers.Remove(annotation.Layer)
          End If
      Next
     Next
     'Save and close the PDF document instance
     loadedDocument.Save("FlattenOutput.pdf")
     loadedDocument.Close(True)
   

By executing the program, you will get the PDF document as follows.

A complete work sample for flattening the annotation on a specific layer form existing PDF can be downloaded from Flatten-Annotation-specific_layer.zip

Take a moment to peruse the documentation, where you can find options like adding layers in a PDF document, adding annotation to layer, nested layers, and toggling the visibility of layers with code examples.

Refer here to explore the rich set of Essential Studio project.

Conclusion

I hope you enjoyed learning about how to flatten the annotation on a specific layer from an existing PDF.

You can refer to our WinForms PDF page to know about its other groundbreaking feature representations and documentation, and how to quickly get started for configuration specifications.

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