Attachments (3)
PDF attachments allow users to see more details on a particular point by visiting attachments inside the PDF. Basically, there are two types of attachments in PDF: document level attachment and annotation attachment. Below are the differences between them.
- Document Level Attachment (represented by PdfAttachment class): A file attached to a PDF at the document level won't appear on a page, but only appear in the PDF reader's "Attachments" panel.
- Annotation Attachment (represented by PdfAttachmentAnnotation class): A file that is attached to a specific position of a page. Annotation attachments are shown as a paper clip icon on the page; reviewers can double-click the icon to open the file.
In this article, you will learn how to extract these two kinds of attachments from a PDF document in C# and VB.NET using Spire.PDF for .NET.
Install Spire.PDF for .NET
To begin with, you need to add the DLL files included in the Spire.PDF for.NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.
PM> Install-Package Spire.PDF
Extract Attachments from PDF in C# and VB.NET
The document level attachments of a PDF document can be obtained through PdfDocument.Attachments property. The following steps illustrate how to extract all document level attachments from a PDF document and save them to a local folder.
- Create a PdfDocument object.
- Load a PDF file using PdfDocument.LoadFromFile() method.
- Get the attachment collection from the document through PdfDocument.Attachments property.
- Get the data of a specific attachment through PdfAttachment.Data property.
- Write the data to a file and save to a specified folder.
- C#
- VB.NET
using Spire.Pdf;
using Spire.Pdf.Attachments;
using System.Net.Mail;
namespace ExtractAttachments
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Load a PDF file that contains attachments
doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Attachments.pdf");
//Get the attachment collection of the PDF document
PdfAttachmentCollection attachments = doc.Attachments;
//Specific output folder path
string outputFolder = "C:\\Users\\Administrator\\Desktop\\output\\";
//Loop through the collection
for (int i = 0; i < attachments.Count; i++)
{
//Write attachment to a file
File.WriteAllBytes(outputFolder + attachments[i].FileName, attachments[i].Data);
}
}
}
}
Extract Annotation Attachments from PDF in C# and VB.NET
Annotation attachment is a page-based element. To get annotations from a specific page, use PdfPageBase.AnnotationsWidget property. After that, you’ll need to determine if a specific annotation is an annotation attachment. The follows are the steps to extract annotation attachments from a PDF document and save them to a local folder.
- Create a PdfDocument object.
- Load a PDF file using PdfDocument.LoadFromFile() method.
- Get a specific page from the document through PdfDocument.Pages[] property.
- Get the annotation collection from the page through PdfPageBase.AnnotationsWidget property.
- Determine if a specific annotation is an instance of PdfAttachmentAnnotationWidget. If yes, write the annotation attachment to a file and save it to a specified folder.
- C#
- VB.NET
using Spire.Pdf;
using Spire.Pdf.Annotations;
namespace ExtractAnnotationAttachments
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Load a PDF file that contains attachments
doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\AnnotationAttachments.pdf");
//Specific output folder path
string outputFolder = "C:\\Users\\Administrator\\Desktop\\Output\\";
//Loop through the pages
for (int i = 0; i < doc.Pages.Count; i++)
{
//Get the annotation collection
PdfAnnotationCollection collection = doc.Pages[i].AnnotationsWidget;
//Loop through the annotations
for (int j = 0; j < collection.Count; j++)
{
//Determine if an annotation is an instance of PdfAttachmentAnnotationWidget
if (collection[j] is PdfAttachmentAnnotationWidget)
{
//Write annotation attachment to a file
PdfAttachmentAnnotationWidget attachmentAnnotation = (PdfAttachmentAnnotationWidget)collection[j];
String fileName = Path.GetFileName(attachmentAnnotation.FileName);
File.WriteAllBytes(outputFolder + fileName, attachmentAnnotation.Data);
}
}
}
}
}
}
Apply for a Temporary License
If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.
Besides text and graphics, PDF files can contain entire files inside them as attachments. This makes the exchange of sets of documents much easier and more reliable. Spire.PDF allows you to attach files in two ways:
- Document Level Attachment: A file attached to a PDF at the document level won't appear on a page, but can only be viewed in the "Attachments" panel of a PDF reader.
- Annotation Attachment: A file will be added to a specific position of a page. Annotation attachments are shown as a paper clip icon on the page; reviewers can double-click the icon to open the file.
This article demonstrates how to add or remove these two types of attachments in a PDF document in C# and VB.NET using Spire.PDF for .NET.
- Add an Attachment to PDF in C# and VB.NET
- Add an Annotation Attachment to PDF in C# and VB.NET
- Remove Attachments from PDF in C# and VB.NET
- Remove Annotation Attachments from PDF in C# and VB.NET
Install Spire.PDF for .NET
To begin with, you need to add the DLL files included in the Spire.PDF for.NET package as references in your .NET project. The DLLs files can be either downloaded from this link or installed via NuGet.
PM> Install-Package Spire.PDF
Add an Attachment to PDF in C# and VB.NET
Adding an attachment to the "Attachments" panel can be easily done by using PdfDocument.Attachments.Add() method. The following are the detailed steps.
- Create a PdfDocument object.
- Load a PDF document using PdfDocument.LoadFromFile() method.
- Create a PdfAttachment object based on an external file.
- Add the attachment to PDF using PdfDocument.Attachments.Add() method.
- Save the document to another PDF file using PdfDocument.SaveToFile() method.
- C#
- VB.NET
using Spire.Pdf;
using Spire.Pdf.Attachments;
namespace AttachFilesToPDF
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Load a sample PDF file
doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Sample.pdf");
//Create a PdfAttachment object based on an external file
PdfAttachment attachment = new PdfAttachment("C:\\Users\\Administrator\\Desktop\\Data.xlsx");
//Add the attachment to PDF
doc.Attachments.Add(attachment);
//Save to file
doc.SaveToFile("Attachment.pdf");
}
}
}
Add an Annotation Attachment to PDF in C# and VB.NET
An annotation attachment can be found in the "Attachments" panel as well as on a specific page. Below are the steps to add an annotation attachment to PDF using Spire.PDF for .NET.
- Create a PdfDocument object.
- Load a PDF document using PdfDocument.LoadFromFile() method.
- Get a specific page to add annotation through PdfDocument.Pages[] property.
- Create a PdfAttachmentAnnotation object based on an external file.
- Add the annotation attachment to the page using PdfPageBase.AnnotationsWidget.Add() method.
- Save the document to another PDF file using PdfDocument.SaveToFile() method.
- C#
- VB.NET
using Spire.Pdf;
using Spire.Pdf.Annotations;
using Spire.Pdf.Graphics;
using System;
using System.Drawing;
using System.IO;
namespace AnnotationAttachment
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Load a sample PDF file
doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Sample.pdf");
//Get a specific page
PdfPageBase page = doc.Pages[0];
//Draw a label on PDF
String label = "Here is the report:";
PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", 13f, FontStyle.Bold), true);
float x = 35;
float y = doc.Pages[0].ActualSize.Height - 220;
page.Canvas.DrawString(label, font, PdfBrushes.Red, x, y);
//Create a PdfAttachmentAnnotation object based on an external file
String filePath = "C:\\Users\\Administrator\\Desktop\\Report.pptx";
byte[] data = File.ReadAllBytes(filePath);
SizeF size = font.MeasureString(label);
RectangleF bounds = new RectangleF((float)(x + size.Width + 5), (float)y, 10, 15);
PdfAttachmentAnnotation annotation = new PdfAttachmentAnnotation(bounds, "Report.docx", data);
annotation.Color = Color.Purple;
annotation.Flags = PdfAnnotationFlags.Default;
annotation.Icon = PdfAttachmentIcon.Graph;
annotation.Text = "Click here to open the file";
//Add the attachment annotation to PDF
page.AnnotationsWidget.Add(annotation);
//Save to file
doc.SaveToFile("Annotation.pdf");
}
}
}
Remove Attachments from PDF in C# and VB.NET
The attachments of a PDF document can be accessed by the PdfDocument.Attachments property, and can be removed by using RemoveAt() method or Clear() method of the PdfAttachmentCollection object. The detailed steps are as follows.
- Create a PdfDocument object.
- Load a PDF document using PdfDocument.LoadFromFile() method.
- Get the attachment collection from the document through PdfDocument.Attachments property.
- Remove a specific attachment using PdfAttachmentCollection.RemoveAt() method. To remove all attachments at once, use PdfAttachmentCollection.Clear() method.
- Save the document to another PDF file using PdfDocument.SaveToFile() method.
- C#
- VB.NET
using Spire.Pdf;
using Spire.Pdf.Attachments;
namespace RemoveAttachments
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Load a PDF file
doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Attachment.pdf");
//Get attachment collection
PdfAttachmentCollection attachments = doc.Attachments;
//Remove a specific attachment
attachments.RemoveAt(0);
//Remove all attachments
//attachments.Clear();
//save to file
doc.SaveToFile("DeleteAttachments.pdf");
}
}
}
Remove Annotation Attachments from PDF in C# and VB.NET
Annotation is a page-based element. To get all annotations from a document, we must traverse through the pages and get the annotations from each page. Then determine if a certain annotation is an annotation attachment. Lastly, remove the annotation attachment from the annotation collection using Remove() method. The following are the detailed steps.
- Create a PdfDocument object.
- Load a PDF document using PdfDocument.LoadFromFile() method.
- Loop through the pages in the document, and get the annotation collection from a specific page through PdfDocument.Pages[].AnnotationsWidget property.
- Determine if an annotation is an instance of PdfAttachmentAnnotationWidget. If yes, remove the annotation attachment using PdfAnnotationCollection.Remove() method.
- Save the document to another PDF file using PdfDocument.SaveToFile() method.
- C#
- VB.NET
using Spire.Pdf;
using Spire.Pdf.Annotations;
namespace RemoveAnnotationAttachments
{
class Program
{
static void Main(string[] args)
{
//Create a PdfDocument object
PdfDocument doc = new PdfDocument();
//Load a PDF file
doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\Annotation.pdf");
//Loop through the pages
for (int i = 0; i < doc.Pages.Count; i++)
{
//Get the annotation collection
PdfAnnotationCollection annotationCollection = doc.Pages[i].AnnotationsWidget;
//Loop through the annotations
for (int j = 0; j < annotationCollection.Count; j++)
{
//Determine if an annotation is an instance of PdfAttachmentAnnotationWidget
if (annotationCollection[j] is PdfAttachmentAnnotationWidget)
{
//Remove the annotation attachment
annotationCollection.Remove((PdfAnnotation)annotationCollection[j]);
}
}
}
//Save to file
doc.SaveToFile("DeleteAnnotationAttachments.pdf");
}
}
}
Apply for a Temporary License
If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.
Different from Word and Excel, PDF enables people to attach various files in it. For the convenience of both protecting the confidential files and avoiding the PDF too large, PDF also allows developers to remove any attachment. This section will introduce a solution to remove attachments from PDF via a PDF component in C#, VB.NET.
Spire.PDF for .NET, a .NET component with rich capabilities in manipulating PDF, enables you to quickly remove attachments from your PDF document. Now please see below picture and view the whole attachments remove solution after it.
In the solution, first you need a decision procedure to see whether this PDF file has any attachment, then, remove attachments. There are two situations here. One is to remove all the attachments. You can call this method: Document.Attachments.Clear(). The other is to remove a certain attachment or attachments. You can remove them either by pointing file name for example filename=="e-iceblue.html " or by the file extension such as filename.Contains(".html"). Below solution directly find the PDF via file name. Please remember to download Spire.PDF for .NET before performing the project.
using Spire.Pdf;
using Spire.Pdf.Attachments;
using System;
using System.Windows.Forms;
namespace RemoveAttachments
{
class Program
{
private void button1_Click(object sender, EventArgs e)
{
OpenFileDialog dialog = new OpenFileDialog();
dialog.Filter = "PDF document(*.pdf)|*.pdf";
DialogResult result = dialog.ShowDialog();
if (result == DialogResult.OK)
{
PdfDocument doc = new PdfDocument();
doc.LoadFromFile(dialog.FileName);
PdfAttachmentCollection attachments = doc.Attachments;
PdfAttachment attachment = null;
if (doc.Attachments.Count > 0)
{
foreach (PdfAttachment oneAttachment in doc.Attachments)
{
string filename = oneAttachment.FileName;
if (filename == "excel.xlsx")
{
attachment = oneAttachment;
break;
}
}
}
if (attachment != null)
{
doc.Attachments.Remove(attachment);
}
doc.SaveToFile("test.pdf");
System.Diagnostics.Process.Start("test.pdf");
}
}
}
}
Imports Spire.Pdf
Imports Spire.Pdf.Attachments
Imports System.Windows.Forms
Namespace RemoveAttachments
Class Program
Private Sub button1_Click(sender As Object, e As EventArgs)
Dim dialog As New OpenFileDialog()
dialog.Filter = "PDF document(*.pdf)|*.pdf"
Dim result As DialogResult = dialog.ShowDialog()
If result = DialogResult.OK Then
Dim doc As New PdfDocument()
doc.LoadFromFile(dialog.FileName)
Dim attachments As PdfAttachmentCollection = doc.Attachments
Dim attachment As PdfAttachment = Nothing
If doc.Attachments.Count > 0 Then
For Each oneAttachment As PdfAttachment In doc.Attachments
Dim filename As String = oneAttachment.FileName
If filename = "excel.xlsx" Then
attachment = oneAttachment
Exit For
End If
Next
End If
If attachment IsNot Nothing Then
doc.Attachments.Remove(attachment)
End If
doc.SaveToFile("test.pdf")
System.Diagnostics.Process.Start("test.pdf")
End If
End Sub
End Class
End Namespace
Spire.PDF is a .NET PDF component, which enables users to perform a wide range of PDF processing tasks directly, such as generate, read, write and modify PDF document in WPF, .NET and Silverlight.
