itextsharp merge pdf

What is iTextSharp?

iTextSharp is a .NET port of the iText Java library, renowned for its robust capabilities in PDF creation and manipulation. It's an open-source library that empowers developers to generate, modify, parse, and inspect PDF documents programmatically. With iTextSharp, you can create complex PDF reports, add watermarks, digitally sign documents, and, of course, merge multiple PDFs into a single file. This library provides a comprehensive toolkit for advanced PDF processing.

It's important to note that iTextSharp (versions 5 and earlier) has been superseded by iText 7. While iTextSharp remains functional, it's recommended to either use iText 7 for new projects or plan a transition for existing projects utilizing iTextSharp. iText 7 offers improved performance, enhanced features, and a more modern architecture, ensuring better compatibility and future-proofing for your PDF manipulation tasks.

Setting Up iTextSharp

Before you can start merging PDFs with iTextSharp, you need to set up the library in your .NET environment. The most straightforward way to install iTextSharp is through the NuGet Package Manager. Open your Visual Studio project, navigate to "Tools" -> "NuGet Package Manager" -> "Manage NuGet Packages for Solution...", and search for "itextsharp". Once found, install the `iTextSharp` package to add it to your project references.

After installation, verify that iTextSharp is correctly added to your solution. Check the "References" section of your project in the Solution Explorer; you should see `itextsharp` listed there. A successful installation confirms that you can now utilize the iTextSharp classes and methods in your code to manipulate PDF documents. Once it has been installed, you can merge pdfs. For creating forms, you can use BreezePDF to easily create fillable PDFs.

In certain scenarios, particularly within SharePoint environments, you might need to add the iTextSharp DLL to the Global Assembly Cache (GAC). This allows iTextSharp to be accessed by multiple applications on the server. Consult your SharePoint documentation for specific instructions on adding DLLs to the GAC, as the process can vary depending on the SharePoint version.

Methods for Merging PDFs with iTextSharp

iTextSharp offers several approaches to merging PDFs, each suitable for different situations and versions of the library. Below, we'll explore three common methods: using `PdfCopy` (for iTextSharp 5 and earlier), using `PdfMerger` (for iText 7 and later), and merging PDF byte arrays.

using iTextSharp.text;
using iTextSharp.text.pdf;
using System.IO;

public void MergePdfFiles(string[] filePaths, string outputPath)
{
    using (var stream = new FileStream(outputPath, FileMode.Create))
    {
        var document = new Document();
        var pdfCopy = new PdfCopy(document, stream);
        document.Open();

        foreach (string filePath in filePaths)
        {
            PdfReader reader = null;
            try {
               reader = new PdfReader(filePath);

               for (int i = 1; i <= reader.NumberOfPages; i++)
                {
                    pdfCopy.AddPage(pdfCopy.GetImportedPage(reader, i));
                }
            } finally {
             if (reader != null)
                    reader.Close();
            }
        }

        document.Close();
    }
}

using iText.Kernel.Pdf;
using System.IO;

public void MergePdfFiles(string[] filePaths, string outputPath)
{
    using (var writer = new PdfWriter(outputPath))
    {
        using (var pdfDocument = new PdfDocument(writer))
        {
            using (var merger = new PdfMerger(pdfDocument))
            {
                foreach (string filePath in filePaths)
                {
                    using (var reader = new PdfReader(filePath))
                    {
                        using (var inputPdfDocument = new PdfDocument(reader))
                        {
                            merger.Merge(inputPdfDocument, 1, inputPdfDocument.GetNumberOfPages());
                        }
                    }
                }
            }
        }
    }
}

using iTextSharp.text;
using iTextSharp.text.pdf;
using System.Collections.Generic;
using System.IO;

public byte[] MergePdfByteArrays(List<byte[]> pdfByteArrays)
{
    using (MemoryStream outputStream = new MemoryStream())
    {
        using (Document document = new Document())
        {
            using (PdfSmartCopy copy = new PdfSmartCopy(document, outputStream))
            {
                document.Open();

                foreach (byte[] pdfBytes in pdfByteArrays)
                {
                    using (PdfReader reader = new PdfReader(pdfBytes))
                    {
                        for (int i = 1; i <= reader.NumberOfPages; i++)
                        {
                            PdfImportedPage page = copy.GetImportedPage(reader, i);
                            copy.AddPage(page);
                        }
                    }
                }

                document.Close();
            }
        }

        return outputStream.ToArray();
    }
}

Handling Different Page Sizes

When merging PDFs with iTextSharp, you might encounter files with different page sizes. By default, iTextSharp preserves the original page sizes during the merging process. This means that the resulting PDF will contain pages of varying dimensions. While this might be acceptable in some cases, it can lead to a visually inconsistent document if the size differences are significant.

To ensure a uniform appearance, you might need to resize pages during the merging process. This involves scaling the content of each page to fit a specific target size. iTextSharp provides the tools to achieve this, allowing you to programmatically adjust the page dimensions. This ensures that all pages in the merged PDF adhere to a consistent size, providing a polished and professional look. If all you need is a fast and simple PDF creator, you can also use BreezePDF!

Here's a code snippet illustrating how to resize pages to A5 during merging:

using iTextSharp.text;
using iTextSharp.text.pdf;
using System.IO;

public void MergeAndResizePdfFiles(string[] filePaths, string outputPath)
{
    using (var stream = new FileStream(outputPath, FileMode.Create))
    {
        Document document = new Document(PageSize.A5);
        PdfCopy pdfCopy = new PdfCopy(document, stream);
        document.Open();

        foreach (string filePath in filePaths)
        {
            PdfReader reader = null;
            try {
              reader = new PdfReader(filePath);

              for (int i = 1; i <= reader.NumberOfPages; i++)
                {
                    PdfImportedPage page = pdfCopy.GetImportedPage(reader, i);
                    PdfContentByte contentByte = pdfCopy.DirectContent;
                    contentByte.AddTemplate(page, 1f, 0, 0, 1f, 0, 0);
                    document.NewPage();
                }
            } finally {
             if (reader != null)
                reader.Close();
            }
        }

        document.Close();
    }
}

Advanced Merging Techniques (Optional)

Beyond basic merging, iTextSharp offers advanced techniques for more complex scenarios. These include merging specific pages from different PDFs and reordering pages during the merge process. These advanced features allow you to have fine-grained control over the structure and content of the merged document.

For instance, you might want to extract only the first few pages from one PDF and combine them with the last few pages from another. Or, you might need to reorder the pages to create a specific flow in the merged document. ITextSharp provides the methods and classes necessary to implement these advanced merging strategies, giving you maximum flexibility in your PDF manipulation tasks.

Troubleshooting Common Issues

When working with iTextSharp, you might encounter certain common issues. One frequent error is "PdfCopy does not contain a definition for CopyAcroForm". This typically arises due to version conflicts or missing dependencies. Ensure you are using a compatible version of iTextSharp and that all necessary dependencies are correctly referenced in your project. Another potential problem is content getting cut off during merging. This can occur when the page sizes or margins are not properly aligned. Adjusting the page size and margins in your code can often resolve this issue. You can also merge files directly using BreezePDF.

BreezePDF as an Alternative

While iTextSharp offers powerful PDF manipulation capabilities, it can be complex and require coding expertise. For simpler PDF merging tasks, BreezePDF provides a user-friendly alternative. BreezePDF is designed for ease of use, offering a straightforward interface for merging, splitting, and editing PDFs without the need for programming. With BreezePDF, you can quickly combine multiple PDFs into a single document with just a few clicks.

BreezePDF's advantages include its intuitive interface, ease of use, and specific functionalities tailored for common PDF tasks. It's an ideal solution for users who need to merge PDFs quickly and efficiently without the complexity of iTextSharp. You can also quickly create fillable pdfs using BreezePDF as well.

Conclusion

In conclusion, iTextSharp provides a robust and versatile library for merging PDFs, offering various methods and advanced techniques to handle complex scenarios. Whether you're using `PdfCopy`, `PdfMerger`, or merging byte arrays, iTextSharp empowers you to programmatically control the merging process. However, for simpler PDF merging tasks, BreezePDF offers a user-friendly alternative that requires no coding. It provides a simple solution to merge PDF files.

Ultimately, the choice between iTextSharp and BreezePDF depends on your specific needs and technical expertise. If you require advanced customization and programmatic control, iTextSharp is the preferred choice. If you prioritize simplicity and ease of use, BreezePDF is an excellent alternative. Explore BreezePDF.com today and discover a seamless solution for all your PDF manipulation needs. With a simple click, you can achieve the same results.