This short guide assists you in how to attach a file to a PDF in C#. It shares a list of steps required to write the program, and the necessary resources required to run the sample code demonstrating how to add attachments to PDF in C#. This operation does not require any third-party tool or software and can be performed in any of the operating systems supporting the .NET platform.

Steps to Insert Attachment in PDF in C#

1. Set the environment to use Aspose.PDF for .NET for attaching a file to a PDF
2. Open the target PDF file using the Document class where the attachment is to be added
3. Instantiate the FileSpecification class object by providing the file name and description
4. Call the Add() method in the EmbeddedFiles collection of the loaded PDF file
5. Save the resultant PDF file on the disk having an attachment in it

These steps summarize the process of how to add attachment in PDF in C#. Each PDF file has a collection of embedded files where new files can be added as attachments to the PDF. The FileSpecification class object is required to be initiated as it is required for adding to this collection.

Code to Add Attachment in PDF in C#

This sample code shows how to attach files to PDF in C#. Firstly, the FileSpecification class object is initiated that has multiple constructors taking file names, file streams, file descriptions, and annotations in different combinations. Similarly, the Add() method in the EmbeddedFiles property of the PDF file has multiple overloaded methods that take the key for the file and the FileSpecification class object for defining the attachment file.

In this topic, we have observed the process to insert file in PDF in C#. If you want to learn the process to add digital signatures in a PDF file, refer to the article on how to add digital signature to PDF in C#.