Multi Threaded Generation

IronPDF provides thread-safe PDF generation and offers support for multi-threading processes when it comes to generating PDF documents with the ChromePdfRenderer class as seen in this example. This way, you can handle PDF generation tasks of any size, or batch PDF generation tasks, concurrently without the fear of running into issues such as thread blocking.

Steps to Multi-Threaded PDF Generation

using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using IronPdf;

public class PdfGenerationExample
{
    public async Task GeneratePdfsAsync()
    {
        // Create an instance of ChromePdfRenderer
        var renderer = new ChromePdfRenderer();

        // Define a list of HTML strings to be converted into PDFs
        var htmlStrings = new List<string>() 
        {
            "<h1>Html#1</h1>", 
            "<h1>Html#2</h1>", 
            "<h1>Html#3</h1>"
        };

        // Use asynchronous programming to render HTML strings to PDFs concurrently
        Task<PdfDocument[]> task = Task.WhenAll(
            htmlStrings.Select(html => renderer.RenderHtmlAsPdfAsync(html))
        );

        // Retrieve the results when all tasks are complete
        List<PdfDocument> pdfList = (await task).ToList();

        // Further manipulation of the PDF documents can be done with pdfList
    }
}

using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using IronPdf;

public class PdfGenerationExample
{
    public async Task GeneratePdfsAsync()
    {
        // Create an instance of ChromePdfRenderer
        var renderer = new ChromePdfRenderer();

        // Define a list of HTML strings to be converted into PDFs
        var htmlStrings = new List<string>() 
        {
            "<h1>Html#1</h1>", 
            "<h1>Html#2</h1>", 
            "<h1>Html#3</h1>"
        };

        // Use asynchronous programming to render HTML strings to PDFs concurrently
        Task<PdfDocument[]> task = Task.WhenAll(
            htmlStrings.Select(html => renderer.RenderHtmlAsPdfAsync(html))
        );

        // Retrieve the results when all tasks are complete
        List<PdfDocument> pdfList = (await task).ToList();

        // Further manipulation of the PDF documents can be done with pdfList
    }
}

Imports System.Collections.Generic
Imports System.Linq
Imports System.Threading.Tasks
Imports IronPdf

Public Class PdfGenerationExample
	Public Async Function GeneratePdfsAsync() As Task
		' Create an instance of ChromePdfRenderer
		Dim renderer = New ChromePdfRenderer()

		' Define a list of HTML strings to be converted into PDFs
		Dim htmlStrings = New List(Of String)() From {"<h1>Html#1</h1>", "<h1>Html#2</h1>", "<h1>Html#3</h1>"}

		' Use asynchronous programming to render HTML strings to PDFs concurrently
		Dim task As Task(Of PdfDocument()) = System.Threading.Tasks.Task.WhenAll(htmlStrings.Select(Function(html) renderer.RenderHtmlAsPdfAsync(html)))

		' Retrieve the results when all tasks are complete
		Dim pdfList As List(Of PdfDocument) = (Await task).ToList()

		' Further manipulation of the PDF documents can be done with pdfList
	End Function
End Class

The first step in generating PDF documents in a multi-threaded environment is to create a new ChromePdfRenderer instance. This gives us access to IronPDF's powerful rendering engine, capable of producing pixel-perfect PDF documents. Then, we will create a new List of string objects, called htmlStrings. This list is full of the HTML strings that we will be generating PDF documents from in our Multi-Threaded environment.

Next, we need to use asynchronous programming to render all of our HTML strings to PDF files concurrently. htmlStrings.Select(html => renderer.RenderHtmlAsPdfAsync(html)) iterates over our list of HTML strings and calls the RenderHtmlAsPdfAsync method, accessed through the renderer, on each string found, converting them into PDF documents. Task.WhenAll() is used to accumulate the asynchronous tasks into a single task that will be completed once all of the individual RenderHtmlAsPdfAsync calls are finished. Then, it will return a new array of PdfDocument objects.

Finally, we will retrieve the results of our PDF generation. await task ensures that the current asynchronous method waits until all the asynchronous PDF rendering tasks are complete and retrieves the resulting array of PdfDocument objects. ToList() then converts the array of PdfDocument objects into the pdfList List for easier further manipulation of the PDF documents.

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