DRIT.Pdf 26.9.1325

DRIT.Pdf

Pure-Managed .NET PDF Document Library

Create, Read, Manipulate, Sign, and Convert PDF Documents

DRIT.Pdf is a pure-managed, cross-platform .NET library for creating, reading, and manipulating PDF documents — PDF with full support for AcroForms, digital signatures (PKCS#12, PKCS#11, PAdES), encryption, a complete annotation hierarchy, tagged PDFs and PDF/UA, PDF/A & PDF/X conformance, portfolios, and document comparison — without relying on any external software dependencies.

Key Benefits

• Pure managed C# implementation with minimal NuGet dependencies
• Consistent rendering results across Windows, Linux, macOS
• Seamless migration path from GemBox.Pdf and Aspose.PDF
• Full annotation hierarchy, AcroForm model, and tagged-PDF structure tree
• PDF/A-1b/2u/3b and PDF/X-4 conformance writing
• Integrated with DRIT.Drawing for advanced graphics and font support

Cross-Platform PDF Library

DRIT.Pdf targets .NET Framework 4.8, .NET 6.0, and .NET 8.0, so it runs on:

• Operating Systems: Windows, Linux, macOS
• Frameworks: .NET Framework 4.8, .NET 6.0, .NET 8.0
• Dependencies: DRIT.Drawing; System.Security.Cryptography.Pkcs (.NET 6.0+); System.Memory (.NET Framework 4.8)

Features

Document I/O

• Create — generate new PDF documents from scratch
• Load/Save — read from and write to file or stream, with load options (password)
• Merge & Split — Pages.AddClone for document merging and page extraction
• Incremental Update — lightweight SaveOptions.Incremental edits without rewriting the file

Pages

• Page tree operations with inherited MediaBox/Rotate
• Page size, rotation, and boundary boxes (Media, Crop, Bleed, Trim, Art)
• Page layout (PageLayout) and page mode (PageMode)
• Viewer preferences (hide toolbar, fit window, direction, …)

Content & Drawing

• FormattedText with font family, size, weight, style, color, and max text width
• PathContent — lines, Bezier curves, rectangles, stroke/fill, dash patterns
• PdfImage placement (JPEG, PNG, BMP, TIFF, GIF via DRIT.Drawing)
• Table DOM with rows, columns, borders, and cell content
• Color spaces (DeviceGray/RGB/CMYK, CalGray/RGB, Lab, ICCBased, Indexed, Separation, DeviceN)
• Patterns (tiling, shading) and shadings (axial, radial, free-form/lattice mesh, Coons/tensor patch)

Text Operations

• Text extraction (full document, per page, by region)
• Text search (string and regular expression)
• Text replace (global, per page, first occurrence, regex)
• Text redaction

Annotations

Full annotation hierarchy rooted at Annotation → MarkupAnnotation:

• Link, line, polyline, polygon
• Text markup (highlight, underline, squiggly, strike-out)
• Sticky note, stamp, free text
• Square, circle, ink, caret
• Redaction, file attachment, popup
• Annotation flags, border style, appearance streams, and flatten

Actions

First-class action hierarchy:

• GoToAction, GoToRemoteAction, LaunchAction, UriAction, JavaScriptAction
• ActionCollection on links, form fields, and document open-action

Forms (AcroForm)

• All field types: text, check box, radio button, dropdown, list box, button, toggle button, signature
• Fill, read, and flatten forms
• FDF/XFDF import/export
• Form actions (reset, submit, import/export data)
• XFA storage

Security & Signatures

• Encryption — AES-256, AES-128, RC4 with user/owner passwords and permissions
• Digital signatures — PKCS#12 (PFX) and PKCS#11 (hardware token)
• PAdES — B-B level, DSS dictionary, LTV support
• Signature validation — hash integrity and certificate chain
• Signature workflows — author permission, locked fields, timestamp

Outlines & Navigation

• Bookmark/outline collection with nested items and destinations
• Hyperlinks (internal page, external URI, file launch)
• Table of contents

Tagged PDF & Accessibility

• TaggedContent structure tree with StructureElement
• Table, row, header, cell, paragraph, note structure elements
• PDF/UA support

Conformance

• PDF/A-1b, PDF/A-2u, PDF/A-3b writing via SaveOptions.Conformance
• PDF/X-4 writing

Attachments

• Embedded files (from file/stream with metadata)
• File attachment annotations (icons, description)
• Associated files (/AF relationships)
• Portfolios (folder/field hierarchy, sort levels, collection layout)

Metadata

• Document info (title, author, subject, keywords)
• XMP metadata read/write

Additional Capabilities

• Document comparison (DocumentComparer with difference hierarchy)
• Optional content groups (layers)
• Marked content (tag roles, ActualText)
• Advanced low-level escape hatch (ObjectDictionary)

Supported File Formats

Image export (PDF → JPEG/PNG/TIFF) and printing are provided by the separate DRIT.Pdf.Rendering package (.NET 8.0 only).

Installation

1. Install via NuGet

• Open Microsoft Visual Studio and the NuGet package manager
• Search for "DRIT.Pdf"
• Click Install to download and reference it in your project

2. Install via Package Manager Console

Install-Package DRIT.Pdf

3. Install via .NET CLI

dotnet add package DRIT.Pdf

Code Examples

Create a PDF Document

using DRIT.Pdf;
using DRIT.Pdf.Content;

// Initialize a new PDF document
using var document = new Document();

// Add a page to the document
var page = document.Pages.Add();

// Add a title
using var title = new FormattedText();
title.FontFamily = PdfFontFamily.TimesRoman;
title.FontSize = 24;
title.FontWeight = PdfFontWeight.Bold;
title.Append("Annual Research Report 2025");
page.Content.DrawText(title, new PdfPoint(72, page.Height - 100));

// Save the document
document.Save("output.pdf");

Merge PDF Documents

using DRIT.Pdf;

// Merge multiple documents into one
using var merged = new Document();
foreach (var path in new[] { "chapter1.pdf", "chapter2.pdf", "chapter3.pdf" })
{
    using var source = Document.Load(path);
    merged.Pages.AddClone(source.Pages);
}

merged.Save("merged.pdf");

// Split: extract each page into a separate document
using var toSplit = Document.Load("merged.pdf");
for (int i = 0; i < toSplit.Pages.Count; i++)
{
    using var single = new Document();
    single.Pages.AddClone(toSplit.Pages[i]);
    single.Save($"page_{i + 1}.pdf");
}

Fill a PDF Form

using DRIT.Pdf;
using DRIT.Pdf.Forms;

// Load PDF with form
using var document = Document.Load("form.pdf");

// Fill a text field by name
document.Form["ParticipantName"].Value = "Sofía Guerrero";

// Tick a check box
var consent = (CheckBoxField)document.Form["ConsentGiven"]!;
consent.IsChecked = true;

// Select a dropdown value
document.Form["Cohort"].Value = "June 2026";

// Save filled document
document.Save("filled.pdf");

Add a Digital Signature

using DRIT.Pdf;
using DRIT.Pdf.Content;
using DRIT.Pdf.Security;

using var document = new Document();
var page = document.Pages.Add();

// Add a visible signature field
var sigField = document.Form.Fields.AddSignature(page, 72, 100, 300, 80);
sigField.Name = "InstructorSignature";
sigField.Appearance.Reason = "Certified by Dr. Petra Holmann";
sigField.Appearance.Location = "TechPath Academy, Berlin";

// Sign with a PFX certificate (PAdES B-B)
var digitalId = new DigitalId("certificate.pfx", "password");
var signer = new Signer(digitalId) { PadesMode = true };
sigField.Sign(signer);

document.Save("signed.pdf");

Encrypt a PDF

using DRIT.Pdf;
using DRIT.Pdf.IO;
using DRIT.Pdf.Security;

using var document = new Document();
document.Pages.Add();

var encryption = new PasswordEncryption
{
    DocumentOpenPassword = "open-password",
    PermissionsPassword = "owner-password",
    Permissions = UserAccessPermissions.PrintHighResolution | UserAccessPermissions.FillForm,
    EncryptionLevel = EncryptionLevel.Aes256
};
document.SaveOptions.Encryption = encryption;

document.Save("encrypted.pdf");

// Open with the correct password
var loaded = Document.Load("encrypted.pdf", new LoadOptions { Password = "open-password" });

Convert PDF to Images

using DRIT.Pdf;
using DRIT.Pdf.IO;
using DRIT.Pdf.Rendering;

using var document = Document.Load("input.pdf");

// Single-page PNG
document.Save("page1.png",
    new ImageSaveOptions(ImageSaveFormat.Png)
    {
        PageNumber = 0,
        PageCount = 1,
        Width = 1200,
        Dpi = 150
    });

// Single-page JPEG
document.Save("page1.jpg",
    new ImageSaveOptions(ImageSaveFormat.Jpeg)
    {
        PageNumber = 0,
        PageCount = 1,
        Width = 1200,
        JpegQuality = 90
    });

System Requirements

• Target Frameworks: .NET Framework 4.8, .NET 6.0, .NET 8.0
• Dependencies: DRIT.Drawing; System.Security.Cryptography.Pkcs (.NET 6.0+); System.Memory (.NET Framework 4.8)
• Optional: DRIT.Pdf.Rendering for image export and printing (.NET 8.0 only)

Documentation

• DRIT.Pdf product page
• Runnable code examples — 40+ standalone console projects
• API Reference (coming soon)

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