Pdfsharpcore

PdfSharpCore

Overview

PdfSharpCore is a .NET Core port of the PdfSharp library for creating and modifying PDF documents. It provides a GDI+-style drawing API (XGraphics) for rendering text, shapes, images, and paths onto PDF pages. PdfSharpCore works entirely in managed code with no native dependencies, making it suitable for cross-platform and containerized environments.

PdfSharpCore is focused on PDF creation and modification. For reading/extracting text from existing PDFs, use PdfPig. For HTML-to-PDF conversion, consider a headless browser approach or QuestPDF for declarative document layout.

Install via NuGet:

dotnet add package PdfSharpCore

Creating a Simple PDF

Create a new PDF document with text and basic formatting.

using PdfSharpCore.Pdf;
using PdfSharpCore.Drawing;

var document = new PdfDocument();
document.Info.Title = "Sample Invoice";
document.Info.Author = "My Application";

var page = document.AddPage();
page.Size = PdfSharpCore.PageSize.A4;

var gfx = XGraphics.FromPdfPage(page);

// Title
var titleFont = new XFont("Arial", 24, XFontStyle.Bold);
gfx.DrawString("INVOICE",
    titleFont, XBrushes.DarkBlue,
    new XRect(0, 40, page.Width, 40),
    XStringFormats.Center);

// Company info
var normalFont = new XFont("Arial", 12);
gfx.DrawString("Acme Corporation", normalFont, XBrushes.Black, 50, 100);
gfx.DrawString("123 Business Ave, Suite 100", normalFont, XBrushes.Gray, 50, 118);
gfx.DrawString("New York, NY 10001", normalFont, XBrushes.Gray, 50, 136);

// Invoice details
var boldFont = new XFont("Arial", 12, XFontStyle.Bold);
gfx.DrawString("Invoice #: INV-2025-001", boldFont, XBrushes.Black, 350, 100);
gfx.DrawString("Date: January 15, 2025", normalFont, XBrushes.Black, 350, 118);
gfx.DrawString("Due: February 14, 2025", normalFont, XBrushes.Black, 350, 136);

document.Save("invoice.pdf");

Drawing Tables

Draw structured tables with headers, rows, and alternating row colors.

using PdfSharpCore.Pdf;
using PdfSharpCore.Drawing;

var document = new PdfDocument();
var page = document.AddPage();
var gfx = XGraphics.FromPdfPage(page);

var headerFont = new XFont("Arial", 11, XFontStyle.Bold);
var cellFont = new XFont("Arial", 10);

// Table configuration
double startX = 50;
double startY = 200;
double[] columnWidths = { 200, 80, 80, 100 };
double rowHeight = 25;
string[] headers = { "Description", "Quantity", "Unit Price", "Total" };

// Draw header row
var headerBrush = new XSolidBrush(XColor.FromArgb(40, 80, 120));
gfx.DrawRectangle(headerBrush,
    startX, startY,
    columnWidths.Sum(), rowHeight);

double x = startX;
for (int i = 0; i < headers.Length; i++)
{
    gfx.DrawString(headers[i], headerFont, XBrushes.White,
        new XRect(x + 5, startY + 5, columnWidths[i] - 10, rowHeight),
        XStringFormats.CenterLeft);
    x += columnWidths[i];
}

// Draw data rows
var data = new[]
{
    new { Description = "Web Development", Qty = "40 hrs", Price = "$150.00", Total = "$6,000.00" },
    new { Description = "UI Design", Qty = "20 hrs", Price = "$120.00", Total = "$2,400.00" },
    new { Description = "Server Hosting", Qty = "1 mo", Price = "$200.00", Total = "$200.00" }
};

for (int row = 0; row < data.Length; row++)
{
    double y = startY + rowHeight * (row + 1);

    // Alternating row background
    if (row % 2 == 0)
    {
        gfx.DrawRectangle(new XSolidBrush(XColor.FromArgb(240, 240, 240)),
            startX, y, columnWidths.Sum(), rowHeight);
    }

    // Row border
    gfx.DrawRectangle(XPens.LightGray,
        startX, y, columnWidths.Sum(), rowHeight);

    // Cell values
    var values = new[] { data[row].Description, data[row].Qty, data[row].Price, data[row].Total };
    x = startX;
    for (int col = 0; col < values.Length; col++)
    {
        gfx.DrawString(values[col], cellFont, XBrushes.Black,
            new XRect(x + 5, y + 5, columnWidths[col] - 10, rowHeight),
            XStringFormats.CenterLeft);
        x += columnWidths[col];
    }
}

document.Save("table-report.pdf");

Drawing Shapes and Lines

Use XGraphics to draw lines, rectangles, ellipses, and paths.

using PdfSharpCore.Pdf;
using PdfSharpCore.Drawing;

var document = new PdfDocument();
var page = document.AddPage();
var gfx = XGraphics.FromPdfPage(page);

// Horizontal rule
gfx.DrawLine(new XPen(XColors.DarkGray, 1), 50, 180, page.Width - 50, 180);

// Filled rectangle with rounded corners
gfx.DrawRoundedRectangle(
    new XPen(XColors.Navy, 2),
    new XSolidBrush(XColor.FromArgb(230, 240, 250)),
    50, 400, 200, 100, 10, 10);

// Circle
gfx.DrawEllipse(XPens.Red, XBrushes.LightPink, 300, 400, 100, 100);

// Dashed line
var dashedPen = new XPen(XColors.Gray, 1)
{
    DashStyle = XDashStyle.Dash
};
gfx.DrawLine(dashedPen, 50, 550, page.Width - 50, 550);

document.Save("shapes.pdf");

Adding Images

Embed images into PDF documents from files or streams.

using System.IO;
using PdfSharpCore.Pdf;
using PdfSharpCore.Drawing;

var document = new PdfDocument();
var page = document.AddPage();
var gfx = XGraphics.FromPdfPage(page);

// Load image from file
var logo = XImage.FromFile("logo.png");

// Draw at specific position and size (maintaining aspect ratio)
double targetWidth = 150;
double aspectRatio = (double)logo.PixelHeight / logo.PixelWidth;
double targetHeight = targetWidth * aspectRatio;
gfx.DrawImage(logo, 50, 30, targetWidth, targetHeight);

// Draw from a stream
using var imageStream = File.OpenRead("photo.jpg");
var photo = XImage.FromStream(() => imageStream);
gfx.DrawImage(photo, 50, 200, 400, 300);

document.Save("with-images.pdf");

Multi-Page Documents with Headers and Footers

Generate multi-page documents with consistent headers, footers, and page numbers.

using PdfSharpCore.Pdf;
using PdfSharpCore.Drawing;

var document = new PdfDocument();
var headerFont = new XFont("Arial", 9, XFontStyle.Italic);
var bodyFont = new XFont("Arial", 11);
var footerFont = new XFont("Arial", 8);

string[] paragraphs = GetReportParagraphs(); // your content source
int totalPages = 3;

for (int pageNum = 1; pageNum <= totalPages; pageNum++)
{
    var page = document.AddPage();
    page.Size = PdfSharpCore.PageSize.A4;
    var gfx = XGraphics.FromPdfPage(page);

    // Header
    gfx.DrawString("Acme Corp - Annual Report 2025",
        headerFont, XBrushes.Gray,
        new XRect(50, 20, page.Width - 100, 20),
        XStringFormats.CenterLeft);
    gfx.DrawLine(XPens.LightGray, 50, 40, page.Width - 50, 40);

    // Body content area
    double yPos = 60;
    // ... render content starting at yPos ...

    // Footer
    gfx.DrawLine(XPens.LightGray, 50, page.Height - 50, page.Width - 50, page.Height - 50);
    gfx.DrawString($"Page {pageNum} of {totalPages}",
        footerFont, XBrushes.Gray,
        new XRect(0, page.Height - 40, page.Width, 20),
        XStringFormats.Center);
    gfx.DrawString("Confidential",
        footerFont, XBrushes.Gray,
        new XRect(50, page.Height - 40, 200, 20),
        XStringFormats.CenterLeft);
}

document.Save("multi-page-report.pdf");

string[] GetReportParagraphs() => new[] { "Content goes here." };

Merging PDF Documents

Combine multiple PDF files into a single document.

using System.Collections.Generic;
using PdfSharpCore.Pdf;
using PdfSharpCore.Pdf.IO;

public class PdfMerger
{
    public void Merge(IEnumerable<string> inputFiles, string outputFile)
    {
        var outputDocument = new PdfDocument();

        foreach (var file in inputFiles)
        {
            var inputDocument = PdfReader.Open(file, PdfDocumentOpenMode.Import);

            for (int i = 0; i < inputDocument.PageCount; i++)
            {
                var page = inputDocument.Pages[i];
                outputDocument.AddPage(page);
            }
        }

        outputDocument.Save(outputFile);
    }
}

// Usage
var merger = new PdfMerger();
merger.Merge(
    new[] { "cover.pdf", "report.pdf", "appendix.pdf" },
    "combined.pdf");

PdfSharpCore vs Other PDF Generators

Best Practices

1. Dispose XGraphics objects or use them within the scope of a single page -- create a new XGraphics for each page rather than reusing across pages.
2. Use XRect with XStringFormats for text alignment instead of manually calculating text positions, which is error-prone and breaks with different font sizes.
3. Calculate page overflow by tracking the Y position of drawn content and adding new pages when content exceeds the page height minus margins.
4. Pre-calculate table column widths based on content or fixed proportions before rendering to avoid text overflow and misaligned columns.
5. Use consistent font instances by creating fonts once and reusing them across pages to reduce object creation and ensure visual consistency.
6. Maintain aspect ratio when drawing images by calculating target dimensions from the original PixelWidth and PixelHeight ratios.
7. Open existing PDFs with PdfDocumentOpenMode.Import when merging, and PdfDocumentOpenMode.Modify when editing in place.
8. Save to a MemoryStream in web applications and return the stream as a file download rather than writing to temporary disk files.
9. Use points (1/72 inch) for all measurements since PdfSharp uses points as its coordinate system -- convert from millimeters by multiplying by 72/25.4.
10. Test generated PDFs in multiple viewers (Adobe Acrobat, Chrome, macOS Preview) since different renderers handle fonts and transparency differently.