How to print a PDF from your Winforms application in C#

Working with PDFs in the way you do with other programming languages, ain't so easy with C#. Pitifully, most of the libraries are commercial and you will need to pay for a license. Other libraries like Spire PDF offers a free version of the library, however it only supports up to 10 pages per PDF and then you will see a watermark message that it's only for test purposes.

In case you are willing to print a PDF from your Winforms application without using a paid API, we'll show you 2 workarounds that will help you to print a PDF file easily.

A. Using Adobe Acrobat

The first way requires that you user has Adobe Acrobat installed. Usually every computer has a program to read PDF files namely Acrobat Reader, so be sure to check that you user has this PDF reader installed.

This method is recommended as it allows the user to choose which pages to print, which printer to use and other settings with the native print dialog:

using System.Diagnostics;
using System.Threading;

public void printPDFWithAcrobat()
{
    string Filepath = @"C:\Users\sdkca\Desktop\path-to-your-pdf\pdf-sample.pdf";

    using (PrintDialog Dialog = new PrintDialog())
    {
        Dialog.ShowDialog();

        ProcessStartInfo printProcessInfo = new ProcessStartInfo()
        {
            Verb = "print",
            CreateNoWindow = true,
            FileName = Filepath,
            WindowStyle = ProcessWindowStyle.Hidden
        };

        Process printProcess = new Process();
        printProcess.StartInfo = printProcessInfo;
        printProcess.Start();

        printProcess.WaitForInputIdle();

        Thread.Sleep(3000);

        if (false == printProcess.CloseMainWindow())
        {
            printProcess.Kill();
        }
    }
}

This code runs the print command in a hidden command line and displays the Print Dialog of the system:

In some Windows versions, the Acrobat Reader may start for a second but it will be automatically closed after you click ok and the file will be printed.

B. Using the RawPrint package

If you don't want to use Acrobat Reader, you may want to use a custom package that sends a file directly to the printer. We are talking about the RawPrint package. RawPrint is a ibrary to send files directly to a Windows printer bypassing the printer driver, it can send PostScript, PCL or other print file types directly to a printer.

To install this library on your project, you can use the NuGet package manager of Visual Studio. Go to the solution explorer of the project in Visual Studio and do right click on your project, from the list select the Manage NuGet Packages option:

Once the Manager shows up, search for the RawPrint library, select (probably) the first option by Tony Edgecombe and click on install:

After the installation you will be able to use the RawPrint class in your project. For more information about this library, please visit the official repository at Github here.

1. List Printer Names

It's recommendable to list all the available printers in some combo box, so the user only needs to select the desired Printer and then print it. You can list all the available printers using the InstalledPrinters property in the PrinterSettings type:

foreach (string printerName in System.Drawing.Printing.PrinterSettings.InstalledPrinters)
{
    Console.WriteLine(printerName);
}

/** Outputs something like:

Send To OneNote 2016
Microsoft XPS Document Writer
Microsoft Print to PDF
Fax
Brother HL-3172CDW series Printer

*/

To use the RawPrint methods, you will need to specify which printer to use. The only way to specify which to use is the name, so be sure to have a name of the printer before sending a file to print. In our case, we have available a real Brother Printer, so we'll use it in this example.

2. Printing PDF

To print the PDF from a file, you only need to use  the PrintRawFile method from an instance of RawPrint. This method expects as first argument, the name of the Printer that you want to use to print the file, as second argument the absolute path to the PDF file (including the filename) that you want to print and as last argument the name of the same file. This last argument is used only to display it as name in the queue:

// Include the namespace of the library
using RawPrint;

/// <summary>
/// Prints a PDF using its RAW data directly to the printer. It requires the nuGET package RawPrint
/// </summary>
public void printPDF()
{
    // Absolute path to your PDF to print (with filename)
    string Filepath = @"C:\Users\sdkca\Desktop\path-to-file\pdf-sample.pdf";
    // The name of the PDF that will be printed (just to be shown in the print queue)
    string Filename = "pdf-sample.pdf";
    // The name of the printer that you want to use
    // Note: Check step 1 from the B alternative to see how to list
    // the names of all the available printers with C#
    string PrinterName = "Brother HL-3172CDW series Printer";

    // Create an instance of the Printer
    IPrinter printer = new Printer();
    
    // Print the file
    printer.PrintRawFile(PrinterName, Filepath, Filename);
}

If you execute the previous code and the file exists, the printer should now doing its Job.

Happy coding !