Merge and combine multiple files into a PDF in C#

This guide explains how to merge multiple PDF files into a single PDF file. It also explains how to combine files of different types into a single PDF file. The procedure explained in this guide works for all supported file types.

Merging multiple PDF files into a single PDF file

To create a single PDF file from multiple PDF files, follow these steps:

  1. Create a GdPictureDocumentConverter object.
  2. Add the file paths of the source PDF documents to a list.
  3. Save the output in a new PDF document with the CombineToPDF method. It takes the following parameters:
    • The list of source file paths.
    • The path to the output PDF file.
    • A member of the PdfConformance enumeration that specifies the conformance level of the output PDF file. For example, use PDF to create a common PDF document.

The example below creates a single PDF document from multiple PDF files:

using GdPictureDocumentConverter gdpictureDocumentConverter = new GdPictureDocumentConverter();
// Add the source PDF documents to a list.
IEnumerable<string> sourceFiles = new List<string>(new string[] {
@"C:\temp\source1.pdf",
@"C:\temp\source2.pdf",
@"C:\temp\source3.pdf",
@"C:\temp\source4.pdf"
});
// Save the output in a new PDF document.
gdpictureDocumentConverter.CombineToPDF(sourceFiles, @"C:\temp\output.pdf", PdfConformance.PDF);

Combining files of different types into a single PDF file

To combine files of different types into a single PDF file, follow these steps:

  1. Create a GdPictureDocumentConverter object.
  2. Add the file paths of the source files to a list.
  3. Save the output in a new PDF document with the CombineToPDF method. It takes the following parameters:
    • The list of source file paths.
    • The path to the output PDF file.
    • A member of the PdfConformance enumeration that specifies the conformance level of the output PDF file. For example, use PDF to create a common PDF document.

The example below creates a single PDF document from files of different types:

using GdPictureDocumentConverter gdpictureDocumentConverter = new GdPictureDocumentConverter();
// Add the source files to a list.
IEnumerable<string> sourceFiles = new List<string>(new string[] {
@"C:\temp\source.png",
@"C:\temp\source.pdf",
@"C:\temp\source.tiff",
@"C:\temp\source.txt"
});
// Save the output in a new PDF document.
gdpictureDocumentConverter.CombineToPDF(sourceFiles, @"C:\temp\output.pdf", PdfConformance.PDF);