Merge PDF Documents

RadPdfProcessing provides support for merging multiple PDF documents into one using the following approaches:

PdfProcessing Content Merging, Splitting, and Adding Demo

Using the RadFixedDocument.Merge Method

You can merge PDF documents out-of-the-box with the Merge method of RadFixedDocument. This method clones the source document and appends it to the current instance of RadFixedDocument:

int timeoutInterval = 100;
string pdfFolderPath = @"..\..\..\Pdf Files";
// Adjust this path to your PDF files directory
string[] pathsCollection = Directory.GetFiles(pdfFolderPath);
RadFixedDocument resultFile = new RadFixedDocument();
PdfFormatProvider pdfFormatProvider = new PdfFormatProvider();

foreach (string path in pathsCollection)
{
    RadFixedDocument document;
    using (Stream stream = File.OpenRead(path))
    {
        document = pdfFormatProvider.Import(stream, TimeSpan.FromSeconds(timeoutInterval));
        resultFile.Merge(document);
    }
} 
string outputFilePath = "merged_by_RadFixedDocument.pdf";
File.Delete(outputFilePath);
using (Stream output = File.OpenWrite(outputFilePath))
{
    pdfFormatProvider.Export(resultFile, output, TimeSpan.FromSeconds(timeoutInterval));
}
Process.Start(new ProcessStartInfo() { FileName = outputFilePath, UseShellExecute = true });

Using the PdfStreamWriter

An alternative approach is using the PdfStreamWriter allowing you to merge pages from different PDF documents:

int timeoutInterval = 100;
string pdfFolderPath = @"..\..\..\Pdf Files";
// Adjust this path to your PDF files directory
string[] pathsCollection = Directory.GetFiles(pdfFolderPath);
RadFixedDocument resultFile;
PdfFormatProvider pdfFormatProvider = new PdfFormatProvider();

using (MemoryStream stream = new MemoryStream())
{
    using (PdfStreamWriter fileWriter = new PdfStreamWriter(stream, leaveStreamOpen: true))
    {
        foreach (string path in pathsCollection)
        {
            using (PdfFileSource fileSource = new PdfFileSource(new MemoryStream(File.ReadAllBytes(path))))
            {
                for (int i = 0; i < fileSource.Pages.Length; i++)
                {
                    PdfPageSource sourcePage = fileSource.Pages[i];
                    using (PdfPageStreamWriter resultPage = fileWriter.BeginPage(sourcePage.Size))
                    {
                        resultPage.WriteContent(sourcePage);
                    }
                }
            }
        }
    }
    resultFile = pdfFormatProvider.Import(stream, TimeSpan.FromSeconds(timeoutInterval));
}

string outputFilePath = "merged_by_PdfStreamWriter.pdf";
File.Delete(outputFilePath);
using (Stream output = File.OpenWrite(outputFilePath))
{
    pdfFormatProvider.Export(resultFile, output, TimeSpan.FromSeconds(timeoutInterval));
}
Process.Start(new ProcessStartInfo() { FileName = outputFilePath, UseShellExecute = true });

The following SDK example is quite useful on this topic as well: SDK Demo.

See Also

• RadFixedDocument
• PdfStreamWriter