Print in an ASP.NET Framework Web App with C#

Updated: August 2, 2026

IronPrint's PrintAsync method enables non-blocking document printing in ASP.NET web applications, preventing UI freezes while processing print requests. This asynchronous approach ensures responsive web apps can handle print operations without blocking threads.

Web applications often need document printing as final output. Integrating print functionality with web applications presents challenges, particularly when dealing with asynchronous operations. IronPrint solves this with the PrintAsync function. This tutorial demonstrates implementing PrintAsync with ASP.NET Core to create a web application that prints documents without blocking.

Before implementation, note that IronPrint provides comprehensive features including printer information retrieval and custom print settings. These capabilities make it ideal for enterprise ASP.NET applications requiring robust printing functionality.

Quickstart: Async PDF Printing in ASP.NET

Install IronPrint via NuGet: Install-Package IronPrint
Import IronPrint into the controller file
Add a print button to trigger the method
Call await Printer.PrintAsync("file.pdf") in the controller action
Verify document printing on button press

1Install IronPrint with NuGet Package Manager
PM > Install-Package IronPrint
```
Install-Package IronPrint
```

2Copy and run this code snippet.

return await IronPrint.Printer.PrintAsync("Basic.pdf");

return await IronPrint.Printer.PrintAsync("Basic.pdf");

3Deploy to test on your live environment

Start using IronPrint in your project today with a free trial

Get started with IronPrint

Start using IronPrint in your project today with a free trial.

First Step:

How to Print in an ASP.NET Web Application

Install the C# printing library from NuGet
Import IronPrint into the controller
Add a print button to trigger the action
Call PrintAsync in the controller method

How Do I Implement Asynchronous PDF Printing in ASP.NET?

This example demonstrates printing a PDF file asynchronously in an ASP.NET Web Application (.NET Framework) project using the PrintAsync method. PrintAsync initiates printing asynchronously, keeping the application responsive compared to synchronous Print methods that block threads.

The asynchronous approach is critical in web applications where multiple users might trigger print operations simultaneously. Unlike the synchronous Print method, PrintAsync ensures your application handles concurrent requests without performance degradation.

Where Should I Add the Print Button?

In your "Index.cshtml" (or home page view), add a button that triggers an action when clicked. This button invokes an ActionResult method in your controller:

@{
    ViewBag.Title = "Home Page";
}

<main>
    <section class="row" aria-labelledby="aspnetTitle">
        <h1 id="title">ASP.NET</h1>
        <p>
            <!-- Button that triggers the PrintPdf ActionResult -->
            <a class="btn btn-primary btn-md" onclick="location.href='@Url.Action("PrintPdf", "Home")'">Print PDF</a>
        </p>
    </section>
</main>

@{
    ViewBag.Title = "Home Page";
}

<main>
    <section class="row" aria-labelledby="aspnetTitle">
        <h1 id="title">ASP.NET</h1>
        <p>
            <!-- Button that triggers the PrintPdf ActionResult -->
            <a class="btn btn-primary btn-md" onclick="location.href='@Url.Action("PrintPdf", "Home")'">Print PDF</a>
        </p>
    </section>
</main>

HTML

ASP.NET application interface showing navigation menu and blue Print PDF button for generating PDFs

How Do I Configure PrintAsync in My Controller?

In your HomeController, implement the PrintAsync method. This method performs print operations asynchronously, enhancing application responsiveness. Before implementing, ensure proper license key configuration for production use.

using IronPrint;
using System.Threading.Tasks;
using System.Web.Mvc;

namespace WebApplication4.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }

        public ActionResult About()
        {
            ViewBag.Message = "Your application description page.";
            return View();
        }

        public ActionResult Contact()
        {
            return View();
        }

        // Action method to handle the printing operation
        // This makes use of the PrintAsync method to avoid blocking the main thread
        public ActionResult PrintPdf()
        {
            // Wait for the asynchronous print operation to complete
            Printer.PrintAsync("Basic.pdf").Wait();

            // Return some view, for example, a confirmation page or the index page
            return View(); // Replace with an appropriate view
        }
    }
}

using IronPrint;
using System.Threading.Tasks;
using System.Web.Mvc;

namespace WebApplication4.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }

        public ActionResult About()
        {
            ViewBag.Message = "Your application description page.";
            return View();
        }

        public ActionResult Contact()
        {
            return View();
        }

        // Action method to handle the printing operation
        // This makes use of the PrintAsync method to avoid blocking the main thread
        public ActionResult PrintPdf()
        {
            // Wait for the asynchronous print operation to complete
            Printer.PrintAsync("Basic.pdf").Wait();

            // Return some view, for example, a confirmation page or the index page
            return View(); // Replace with an appropriate view
        }
    }
}

Imports IronPrint
Imports System.Threading.Tasks
Imports System.Web.Mvc

Namespace WebApplication4.Controllers
	Public Class HomeController
		Inherits Controller

		Public Function Index() As ActionResult
			Return View()
		End Function

		Public Function About() As ActionResult
			ViewBag.Message = "Your application description page."
			Return View()
		End Function

		Public Function Contact() As ActionResult
			Return View()
		End Function

		' Action method to handle the printing operation
		' This makes use of the PrintAsync method to avoid blocking the main thread
		Public Function PrintPdf() As ActionResult
			' Wait for the asynchronous print operation to complete
			Printer.PrintAsync("Basic.pdf").Wait()

			' Return some view, for example, a confirmation page or the index page
			Return View() ' Replace with an appropriate view
		End Function
	End Class
End Namespace

Imports IronPrint
Imports System.Threading.Tasks
Imports System.Web.Mvc

Namespace WebApplication4.Controllers
	Public Class HomeController
		Inherits Controller

		Public Function Index() As ActionResult
			Return View()
		End Function

		Public Function About() As ActionResult
			ViewBag.Message = "Your application description page."
			Return View()
		End Function

		Public Function Contact() As ActionResult
			Return View()
		End Function

		' Action method to handle the printing operation
		' This makes use of the PrintAsync method to avoid blocking the main thread
		Public Function PrintPdf() As ActionResult
			' Wait for the asynchronous print operation to complete
			Printer.PrintAsync("Basic.pdf").Wait()

			' Return some view, for example, a confirmation page or the index page
			Return View() ' Replace with an appropriate view
		End Function
	End Class
End Namespace

For advanced scenarios, implement proper async/await patterns and customize the print operation. Here's an enhanced example demonstrating error handling and custom print settings:

using IronPrint;
using System;
using System.Threading.Tasks;
using System.Web.Mvc;

namespace WebApplication4.Controllers
{
    public class HomeController : Controller
    {
        // Async action method with proper error handling
        public async Task<ActionResult> PrintPdfAdvanced()
        {
            try
            {
                // Create custom print settings
                var printSettings = new PrintSettings
                {
                    // Select specific printer
                    PrinterName = "Microsoft Print to PDF",
                    // Set paper size
                    PaperSize = PaperSize.A4,
                    // Configure orientation
                    PaperOrientation = PaperOrientation.Portrait,
                    // Set number of copies
                    NumberOfCopies = 1,
                    // Configure DPI for high-quality output
                    Dpi = 300
                };

                // Print asynchronously with custom settings
                await Printer.PrintAsync("Basic.pdf", printSettings);

                // Log successful print operation (optional)
                System.Diagnostics.Debug.WriteLine("Document printed successfully");

                // Return success view or redirect
                TempData["PrintMessage"] = "Document sent to printer successfully!";
                return RedirectToAction("Index");
            }
            catch (Exception ex)
            {
                // Handle printing errors gracefully
                System.Diagnostics.Debug.WriteLine($"Printing error: {ex.Message}");
                TempData["ErrorMessage"] = "Unable to print document. Please try again.";
                return RedirectToAction("Index");
            }
        }
    }
}

using IronPrint;
using System;
using System.Threading.Tasks;
using System.Web.Mvc;

namespace WebApplication4.Controllers
{
    public class HomeController : Controller
    {
        // Async action method with proper error handling
        public async Task<ActionResult> PrintPdfAdvanced()
        {
            try
            {
                // Create custom print settings
                var printSettings = new PrintSettings
                {
                    // Select specific printer
                    PrinterName = "Microsoft Print to PDF",
                    // Set paper size
                    PaperSize = PaperSize.A4,
                    // Configure orientation
                    PaperOrientation = PaperOrientation.Portrait,
                    // Set number of copies
                    NumberOfCopies = 1,
                    // Configure DPI for high-quality output
                    Dpi = 300
                };

                // Print asynchronously with custom settings
                await Printer.PrintAsync("Basic.pdf", printSettings);

                // Log successful print operation (optional)
                System.Diagnostics.Debug.WriteLine("Document printed successfully");

                // Return success view or redirect
                TempData["PrintMessage"] = "Document sent to printer successfully!";
                return RedirectToAction("Index");
            }
            catch (Exception ex)
            {
                // Handle printing errors gracefully
                System.Diagnostics.Debug.WriteLine($"Printing error: {ex.Message}");
                TempData["ErrorMessage"] = "Unable to print document. Please try again.";
                return RedirectToAction("Index");
            }
        }
    }
}

Imports IronPrint
Imports System
Imports System.Threading.Tasks
Imports System.Web.Mvc

Namespace WebApplication4.Controllers
    Public Class HomeController
        Inherits Controller

        ' Async action method with proper error handling
        Public Async Function PrintPdfAdvanced() As Task(Of ActionResult)
            Try
                ' Create custom print settings
                Dim printSettings As New PrintSettings With {
                    ' Select specific printer
                    .PrinterName = "Microsoft Print to PDF",
                    ' Set paper size
                    .PaperSize = PaperSize.A4,
                    ' Configure orientation
                    .PaperOrientation = PaperOrientation.Portrait,
                    ' Set number of copies
                    .NumberOfCopies = 1,
                    ' Configure DPI for high-quality output
                    .Dpi = 300
                }

                ' Print asynchronously with custom settings
                Await Printer.PrintAsync("Basic.pdf", printSettings)

                ' Log successful print operation (optional)
                System.Diagnostics.Debug.WriteLine("Document printed successfully")

                ' Return success view or redirect
                TempData("PrintMessage") = "Document sent to printer successfully!"
                Return RedirectToAction("Index")
            Catch ex As Exception
                ' Handle printing errors gracefully
                System.Diagnostics.Debug.WriteLine($"Printing error: {ex.Message}")
                TempData("ErrorMessage") = "Unable to print document. Please try again."
                Return RedirectToAction("Index")
            End Try
        End Function
    End Class
End Namespace

Imports IronPrint
Imports System
Imports System.Threading.Tasks
Imports System.Web.Mvc

Namespace WebApplication4.Controllers
    Public Class HomeController
        Inherits Controller

        ' Async action method with proper error handling
        Public Async Function PrintPdfAdvanced() As Task(Of ActionResult)
            Try
                ' Create custom print settings
                Dim printSettings As New PrintSettings With {
                    ' Select specific printer
                    .PrinterName = "Microsoft Print to PDF",
                    ' Set paper size
                    .PaperSize = PaperSize.A4,
                    ' Configure orientation
                    .PaperOrientation = PaperOrientation.Portrait,
                    ' Set number of copies
                    .NumberOfCopies = 1,
                    ' Configure DPI for high-quality output
                    .Dpi = 300
                }

                ' Print asynchronously with custom settings
                Await Printer.PrintAsync("Basic.pdf", printSettings)

                ' Log successful print operation (optional)
                System.Diagnostics.Debug.WriteLine("Document printed successfully")

                ' Return success view or redirect
                TempData("PrintMessage") = "Document sent to printer successfully!"
                Return RedirectToAction("Index")
            Catch ex As Exception
                ' Handle printing errors gracefully
                System.Diagnostics.Debug.WriteLine($"Printing error: {ex.Message}")
                TempData("ErrorMessage") = "Unable to print document. Please try again."
                Return RedirectToAction("Index")
            End Try
        End Function
    End Class
End Namespace

This enhanced implementation showcases concepts from the Print Settings guide, including specifying printer names, configuring paper sizes, and handling errors appropriately.

When working with printer selection in web environments, leverage the Get Printer Names functionality to dynamically populate available printer lists:

// Get list of available printers
public ActionResult GetAvailablePrinters()
{
    var printers = Printer.GetPrinterNames();
    ViewBag.PrinterList = new SelectList(printers);
    return View();
}

// Get list of available printers
public ActionResult GetAvailablePrinters()
{
    var printers = Printer.GetPrinterNames();
    ViewBag.PrinterList = new SelectList(printers);
    return View();
}

' Get list of available printers
Public Function GetAvailablePrinters() As ActionResult
    Dim printers = Printer.GetPrinterNames()
    ViewBag.PrinterList = New SelectList(printers)
    Return View()
End Function

' Get list of available printers
Public Function GetAvailablePrinters() As ActionResult
    Dim printers = Printer.GetPrinterNames()
    ViewBag.PrinterList = New SelectList(printers)
    Return View()
End Function

For scenarios requiring user interaction, consider implementing a Print with Dialog approach, though this suits desktop applications better than web environments.

Additional Considerations for Production Deployment

When deploying your ASP.NET application with IronPrint, consider these factors:

License Configuration: For ASP.NET applications, configure your license key in Web.config. See the Setting License Key in Web.config guide for proper setup.
Printer Access: Ensure the application pool identity has permissions to access local or network printers. The Print Your Documents documentation provides printer access requirements.
Error Handling: Implement robust error handling for offline printers or inaccessible documents. For technical issues, use the Engineering Request process to resolve complex problems.
Performance: For high-volume printing, implement a queue system to manage print requests efficiently. The asynchronous PrintAsync is ideal for such implementations.

For comprehensive printing capabilities, consult the API Reference for detailed documentation of all methods and properties in the IronPrint namespace.

Frequently Asked Questions

What is the main advantage of using IronPrint's PrintAsync method in ASP.NET web applications?

IronPrint's PrintAsync method enables non-blocking document printing, ensuring your ASP.NET web application remains responsive while handling print requests.

How can I integrate IronPrint into my ASP.NET web application?

To integrate IronPrint, install the library via NuGet, import it into your controller files, add a print button for triggering the print action, and use the PrintAsync method for asynchronous printing.

Why should I choose asynchronous printing in my web application?

Asynchronous printing with IronPrint's PrintAsync prevents UI freezes and allows concurrent handling of multiple print requests, which boosts the responsiveness of your web application.

How can I configure custom print settings using IronPrint?

You can configure custom print settings by creating an instance of PrintSettings, specifying parameters such as printer name, paper size, orientation, copies, and DPI, and passing it to the PrintAsync method.

Where do I add the print button in my ASP.NET web application?

Add the print button in the 'Index.cshtml' or your home page view. This button should invoke an ActionResult method in your controller to trigger printing.

How can I handle errors during the printing process?

Use try-catch blocks around your PrintAsync calls to catch exceptions and handle them gracefully, providing user feedback or logging as necessary.

What should I consider for deploying an ASP.NET application using IronPrint?

Ensure your application's license configuration, printer access permissions, and error handling mechanisms are properly set up in production.

How can I dynamically populate available printer lists in my application?

Use the GetPrinterNames method from IronPrint to retrieve and dynamically display a list of available printers to users.

What is the role of the PrintAsync method in managing high-volume printing?

PrintAsync supports high-volume printing by enabling a queue system that efficiently manages print requests without blocking the application.

Is it possible to use IronPrint for printing with a dialog in a web environment?

While it's possible to integrate a print dialog in desktop applications, this approach is less suitable for web environments, where asynchronous methods are preferred for best performance.

Curtis Chau

Chat with engineering team now

Technical Writer

Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.

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