How to Print in an ASP.NET Web Application Framework

Sometimes, web applications need to print a document as the final output. However, integrating the print function with a web application can be a real-world challenge. Many web applications use asynchronous functions, and a synchronous print function could potentially cause issues. But, there's a solution! IronPrint offers the PrintAsync function, a crucial tool for web applications. In this brief tutorial, we'll demonstrate the power of the PrintAsync function combined with ASP.NET Core. This will show you how to simulate a real-world web application that prints a document as the final output.

Get started with IronPrint

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

First Step:
green arrow pointer


Asynchronous PDF Printing Example

This example demonstrates how to print a PDF file asynchronously in an ASP.NET Web Application (.NET Framework) project using the PrintAsync method. By using PrintAsync, the print operation is initiated asynchronously, allowing the application to remain responsive, as opposed to blocking the thread with traditional synchronous Print methods.

Add a Print Button

In your "Index.cshtml" (or home page view), add a button that triggers an action when clicked. This button will invoke an ActionResult method in your controller. Here’s how you can implement it:

@{
    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

Index page


Implement PrintAsync in the Controller

In your HomeController, you’ll implement the PrintAsync method. This method allows the print operation to occur asynchronously, enhancing the responsiveness of the application.

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
$vbLabelText   $csharpLabel

Frequently Asked Questions

What challenges might arise when trying to print from an ASP.NET web application?

Integrating a print function in a web application can be challenging because many web applications use asynchronous functions, and a synchronous print function could cause issues.

How can asynchronous printing be achieved in ASP.NET applications?

Using a library that provides a `PrintAsync` function is crucial for web applications as it allows the print operation to be performed asynchronously, preventing the application from blocking the main thread.

What is the first step to use a printing library in a web application?

The first step is to download the desired C# library for printing from the NuGet package manager.

How can you trigger a print action in an ASP.NET web application?

You can trigger a print action by adding a button in your view, such as in the 'Index.cshtml' page, which calls an `ActionResult` method in the controller when clicked.

What is the role of an asynchronous print method in the controller?

An asynchronous print method in the controller initiates the print operation asynchronously, allowing the application to remain responsive and not block the main thread.

Can you print PDF files asynchronously in an ASP.NET Web Application?

Yes, you can use a library's `PrintAsync` method to print PDF files asynchronously in an ASP.NET Web Application.

What is an example of triggering a print operation from a button in a view?

In your 'Index.cshtml', you can add a button that uses the `onclick` event to call `location.href='@Url.Action("PrintPdf", "Home")'`, which triggers the print operation.

What should you do after implementing an asynchronous print method in the controller?

After implementing an asynchronous print method, you should verify that the document is printed when the button is pressed to ensure the functionality works as expected.

Chaknith Bin
Software Engineer
Chaknith works on IronXL and IronBarcode. He has deep expertise in C# and .NET, helping improve the software and support customers. His insights from user interactions contribute to better products, documentation, and overall experience.