Split PDF Files in ASP.NET Core

Overview

The Syncfusion ASP.NET core PDF library that allows users to split a PDF file into multiple sub-documents quickly and accurately. It also allows you to split, combine, import, and append PDFs.

Split PDF ASP.NET Core

How to split PDF files in ASP.NET Core

Install the Syncfusion.Pdf.Net.Core NuGet package in your project.
Create FileStream objects to represent input PDF files.
Create a PdfLoadedDocument object by passing the FileStream object.
Create a new PDF document using the PdfDocument class.
Use the ImportPage method of the PdfDocumentBase class to split a PDF document into multiple files.
Save the PdfDocument object to the FileStream object.

Here is an example of how to split PDF files in C# using the Syncfusion ASP.NET Core PDF library. You can split a PDF file into a single page or multiple page PDF document with just a few lines of code.

c#
//Load PDF document as stream
FileStream docStream = new FileStream("Input.pdf", FileMode.Open, FileAccess.Read);
//Load an existing PDF document
PdfLoadedDocument document = new PdfLoadedDocument(docStream);
//Create zip file     
ZipArchive zipArchive = new ZipArchive();
//Iterate over the pages
for (int pageIndex = 0; pageIndex < document.PageCount; pageIndex++)
    {
        //Create a new PdfDocument object
        using (PdfDocument outputDocument = new PdfDocument())
            {
                //Import the page from the loadedDocument to the outputDocument
                outputDocument.ImportPage(document, pageIndex);

                //Save the document
                MemoryStream stream = new MemoryStream();
                outputDocument.Save(stream);
                //Add the files you want to zip
                zipArchive.AddItem(pageIndex + ".pdf", stream, false, (Syncfusion.Compression.FileAttributes)FileAttributes.Normal);
            }
    }
//Zips the filename 
MemoryStream memoryStream = new MemoryStream();
zipArchive.Save(memoryStream, false);
return File(memoryStream.ToArray(), "application/zip", "SplitFiles.zip");

PDF split options

Split a range of pages into a separate PDF document

A range of pages can be split into a separate PDF document.

c#
//Load PDF document as stream
FileStream docStream = new FileStream("Input.pdf", FileMode.Open, FileAccess.Read);
//Load an existing PDF document
PdfLoadedDocument document = new PdfLoadedDocument(docStream);
int[,] values = new int[,] { { 0,2 }, { 2, 4 } };
ZipArchive zipArchive = new ZipArchive();
MemoryStream memoryStream = new MemoryStream();
document.DocumentSplitEvent += (object sender, PdfDocumentSplitEventArgs args) =>
{
    zipArchive.AddItem(Guid.NewGuid().ToString() + ".pdf", args.PdfDocumentData, false, (Syncfusion.Compression.FileAttributes)FileAttributes.Normal);
};
//Split the pages into fixed number
document.SplitByRanges(values);
//Close the document
document.Close(true);
//Add the files you want to zip
zipArchive.Save(memoryStream, false);
return File(memoryStream.ToArray(), "application/zip", "SplitFilesZ.zip");

Import or delete certain pages from a PDF file

Users can get specific pages or delete certain pages from a PDF document.

c#
//Load PDF document as stream
FileStream docStream = new FileStream("Input.pdf", FileMode.Open, FileAccess.Read);
//Load an existing PDF document
using (PdfLoadedDocument document = new PdfLoadedDocument(docStream))
using (PdfDocument outputDocument = new PdfDocument())
    {
        ZipArchive zipArchive = new ZipArchive();
        //Remove the first page in the PDF document  
        document.Pages.RemoveAt(0);
        //Import certain pages to the new PDF document 
        outputDocument.ImportPage(document, 0);
        //Save the document
        MemoryStream stream = new MemoryStream();
        outputDocument.Save(stream);
        //Add the files you want to zip
        zipArchive.AddItem("SplitResult.pdf", stream, false, (Syncfusion.Compression.FileAttributes)FileAttributes.Normal);
        MemoryStream memoryStream = new MemoryStream();
        zipArchive.Save(memoryStream, false);
        return File(memoryStream.ToArray(), "application/zip", "SplitFiles.zip");
    }

Split a document based on bookmarks

Split a PDF document based on bookmarks.

c#
//Load PDF document as stream
FileStream docStream = new FileStream("Input.pdf", FileMode.Open, FileAccess.Read);
//Load the PDF document from stream
using (PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream))
{
    //Create bookmark object
    PdfBookmarkBase bookmarks = loadedDocument.Bookmarks;
    ZipArchive zipArchive = new ZipArchive();
    //Load the PDF document from stream
    foreach (PdfBookmark bookmark in bookmarks)
        {
            if (bookmark.Destination != null)
                {
                    if (bookmark.Destination.Page != null)
                        {
                            int endIndex = bookmark.Destination.PageIndex;
                            //Create a new PDF document
                            using (PdfDocument document = new PdfDocument())
                            {
                                foreach (PdfLoadedBookmark childBookmark in bookmark)
                                {
                                    endIndex = childBookmark.Destination.PageIndex;
                                }
                                //Import the pages to the new PDF document
                                document.ImportPageRange(loadedDocument, bookmark.Destination.PageIndex, endIndex);
                                MemoryStream stream = new MemoryStream();
                                document.Save(stream);
                                //Add the files you want to zip
                                zipArchive.AddItem(bookmark.Title + ".pdf", stream, false, (Syncfusion.Compression.FileAttributes)FileAttributes.Normal);
                            }
                        }
                    }
                }
            MemoryStream memoryStream = new MemoryStream();
            zipArchive.Save(memoryStream, false);
            return File(memoryStream.ToArray(), "application/zip", "SplitFiles.zip");
        }
    }