CodexPdf.Core 1.0.2

CodexPdf.Core

An independent, modern .NET library for creating, reading, and editing PDF documents — pages, text, tables, forms, annotations, digital signatures, encryption, and HTML/DOCX conversion — built on public PDF specifications with no dependency on proprietary PDF SDKs.

Overview

CodexPdf is a from-scratch PDF library for .NET, shipped as a single package (CodexPdf.Core) with no separate installs to track for different features.

It covers document creation, classic PDF reading (plus cross-reference streams and object streams, PDF 1.5+), text extraction and search, drawing (shapes/text/images), tables, bookmarks, hyperlinks, annotations, AcroForm fields, page manipulation, merge/split, RC4/AES-128/AES-256 encryption, PKCS#7/CMS digital signatures, TrueType/OpenType font embedding, raster rendering to bitmaps (including rendering pages from arbitrary third-party PDFs, not just ones this library wrote), PDF/A conformance checking, structural validation, optimization, HTML/DOCX/image/text conversion, Windows printing, ASP.NET Core integration, and a public low-level API for inspecting raw PDF objects.

The project is under active development (pre-1.0) - see Versioning and Changelog for what's stable versus still moving.

Features

• Creation: pages (A0-A5, Letter, Legal, Executive, or custom size), portrait/landscape, margins, background color, metadata, document language, viewer preferences.
• Text: draw text at coordinates or word-wrapped into a rectangle, left/center/right/justify alignment, rich (multi-run) text, TrueType/OpenType font embedding with automatic subsetting, font fallback, Unicode (including CJK via CID/Identity-H fonts).
• Drawing: lines, rectangles, rounded rectangles, circles, ellipses, polygons, polylines, arcs, Bézier curves - stroke/fill color, line width, dash patterns, transparency, rotation, clipping.
• Images: PNG, JPEG, GIF, BMP, TIFF, WebP - load, resize, crop, rotate, compress, position with aspect-ratio preservation.
• Tables: column/row spanning, per-side borders, background/padding/alignment, nested tables, automatic column sizing, repeating header rows across page breaks.
• Headers/footers: page number, total pages, date/time, document title, images, tables, different first-page/odd/even headers.
• Reading: pages, metadata, text, images, annotations, bookmarks, links, form fields, attachments; a public low-level API for arbitrary PDF object traversal.
• Editing: add text/images/shapes/watermarks/annotations to an existing PDF; remove/insert/reorder/rotate/crop pages; update metadata.
• Merge & split: combine documents or files; split by page range, page count, or bookmark.
• Forms: text fields, checkboxes, radio buttons, combo/list boxes, push buttons, signature field placeholders - read, set, clear, and flatten.
• Security: user/owner passwords, RC4/AES-128/AES-256 encryption, printing/copying/editing/form-filling/annotation permission restrictions.
• Digital signatures: PKCS#7/CMS signing with a real X.509 certificate, multiple signatures, signing an encrypted document, incremental signing, signature validation.
• Conversion: HTML→PDF (real HTML5 parsing, CSS cascade and box model, lists, links), DOCX→PDF, images→PDF, text→PDF, PDF→HTML, PDF→text - plus a plugin architecture (IPdfConverter<TInput, TOutput>) for registering your own converters.
• Rendering: rasterize any page - including one from an arbitrary third-party PDF, not just one this library wrote - to a bitmap (PNG/JPEG/TIFF) with configurable DPI, scaling, and anti-aliasing.
• Printing: send a document to a Windows printer.
• ASP.NET Core: IServiceCollection registration and minimal-API/MVC result helpers for serving generated PDFs.
• PDF/A & accessibility: PDF/A-1/2/3 conformance validation, tagged PDF (logical reading order, alt text, heading/table structure).
• Attachments, bookmarks, and hyperlinks: embedded files, nested bookmarks with styling (color/bold/italic), URL/internal/named-destination links.
• Streaming: Save/Open overloads for file paths, byte[], and Stream, with decompression-bomb and oversized-input guards for untrusted PDF input.

Installation

dotnet add package CodexPdf.Core

One package covers everything - creation, reading/editing, digital signatures, HTML/DOCX/image/text conversion, Windows printing, and ASP.NET Core integration. See Dependencies for what it brings in.

Quick Start

using CodexPdf.Core;

using var document = new PdfDocument();
var page = document.AddPage(PdfPageSize.A4);
page.Canvas.DrawText("Hello PDF", new PdfTextStyle { FontSize = 24 }, new PdfPoint(50, 750));
document.Save("hello.pdf");

Usage

Reading and searching

using var document = PdfDocument.Open("input.pdf");
Console.WriteLine($"{document.PageCount} pages, title: {document.Title}");

var text = document.ExtractText();
var matches = document.Search("Invoice Number");

Tables

using var document = new PdfDocument();
var page = document.AddPage(PdfPageSize.A4);

var table = document.CreateTable();
table.AddColumn("Name");
table.AddColumn("Email");
table.AddColumn("Status");
table.AddRow("Ada Lovelace", "ada@example.com", "Active");

document.AddTable(table, page, new PdfRectangle(50, 100, 495, 600));
document.Save("report.pdf");

PDF Operations

Create

using var document = new PdfDocument();
var page = document.AddPage(PdfPageSize.A4);
page.Orientation = PdfPageOrientation.Portrait;
page.Canvas.DrawRectangle(new PdfRectangle(50, 700, 200, 80), strokeColor: "0,0,0", fillColor: "0.9,0.9,1");
document.Metadata.Title = "Sample Report";
document.Save("create.pdf");

Read

using var document = PdfDocument.Open("input.pdf");
foreach (var page in document.Pages)
{
    Console.WriteLine(page.ExtractText(page.CropBox ?? new PdfRectangle(0, 0, page.Width, page.Height)));
}

Edit

using var editable = PdfEditableDocument.Open("input.pdf");
var page = editable.GetPage(1);
page.Rotation = 90;
page.AppendContent.DrawText("DRAFT", new PdfTextStyle { FontSize = 48 }, new PdfPoint(150, 400));
editable.Save("edited.pdf");

Merge

using var merged = PdfDocument.MergeFiles("part1.pdf", "part2.pdf", "part3.pdf");
merged.Save("merged.pdf");

Split

// Byte-range/stream based - doesn't load the whole source document into the object model.
PdfDocument.Split("report.pdf", firstPage: 1, lastPage: 5, "first-five-pages.pdf");

Forms

using var document = new PdfDocument();
var page = document.AddPage(PdfPageSize.A4);
page.AddTextField("FullName", new PdfRectangle(50, 700, 250, 20));
document.Save("form.pdf");

using var reader = PdfReadDocument.Open("form.pdf");
reader.SetTextField("FullName", "Ada Lovelace", "form-filled.pdf");

Convert

using CodexPdf.Core.Conversion;

var document = HtmlToPdf.Convert("<h1>Invoice</h1><p>Thank you for your business.</p>");
document.Save("invoice.pdf");

Security

using var document = new PdfDocument();
document.AddPage(PdfPageSize.A4);

document.Security.UserPassword = "let-me-in";
document.Security.EncryptionAlgorithm = PdfEncryptionAlgorithm.Aes256;
document.Security.AllowPrinting = true;
document.Security.AllowCopying = false;

document.Save("secure.pdf");

Configuration

Register CodexPdf for dependency injection, with configurable defaults:

services.AddPdfProcessing(options =>
{
    options.DefaultPageSize = PdfPageSize.A4;
    options.EnableCompression = true;
});

Serve a generated PDF from a minimal API endpoint:

app.MapGet("/reports/{id}", (int id) =>
{
    using var document = new PdfDocument();
    document.AddPage(PdfPageSize.A4);
    return PdfResults.File(document, $"report-{id}.pdf");
});

Dependencies

CodexPdf.Core is a single package; everything below is included, not a separate install.

Supported Frameworks

Targets .NET 10. Printing calls into System.Drawing.Common/GDI+ and is Windows-only at runtime (PdfPrinter.IsSupported reports this; calling Print elsewhere throws PlatformNotSupportedException). Every other feature is fully cross-platform.

API Reference

Generated from the XML doc comments via DocFX. Build and browse it locally:

dotnet tool install -g docfx   # once
docfx docs/docfx.json --serve  # builds and serves at http://localhost:8080

Examples

• Tutorials - task-oriented walkthroughs: getting started, reading/searching, forms, security/signatures, conversion, rendering, ASP.NET Core integration. Every code example was compiled and run against the actual library before publishing.
• Migration Guide - coming from another .NET PDF library? Start here.
• samples/CodexPdf.Core.Sample - a runnable console sample.

Development

dotnet build CodexPdf.sln
dotnet test CodexPdf.sln

• BENCHMARKS.md - measured throughput/allocation numbers (creation, reading, encryption, rendering, conversion) and instructions to reproduce them.
• THREAD_SAFETY.md - which types are safe to share across threads and which aren't (short version: building a document is not thread-safe, reading one concurrently is).
• SECURITY.md - the encryption implementation's design notes.

Contributing

Contributions are welcome. See CONTRIBUTING.md for the build/test workflow and expectations before opening a pull request. Please don't copy proprietary PDF-library implementations or fixtures - CodexPdf is built independently from public PDF specifications.

Versioning

CodexPdf follows Semantic Versioning. Currently ships as 0.1.0 (pre-1.0): public APIs may still change between minor versions until 1.0.0. Breaking changes are called out explicitly in the Changelog.

Changelog

See CHANGELOG.md for release notes, including breaking changes.

License

MIT - see LICENSE. Third-party dependencies (SkiaSharp, AngleSharp, DocumentFormat.OpenXml, System.Security.Cryptography.Pkcs, System.Drawing.Common) are documented in Dependencies and are all permissively licensed.

Author

Lay Ly

Contact

• Email: lylay.it.kh855@gmail.com
• Phone: +855 10 657 986
• LinkedIn: linkedin.com/in/lay-ly-1292311b3

Support

• Issues - bug reports and feature requests.
• Discussions - questions and general discussion.