killerpdf-portable-editor

# KillerPDF Portable PDF Editor Skill > Skill by [ara.so](https://ara.so) — Daily 2026 Skills collection. KillerPDF is a single-EXE (~6 MB zipped), portable Windows PDF editor for .NET Framework 4.8. It renders PDFs via PDFium (Docnet.Core), supports inline text editing, annotations, freehand drawing, highlights, signatures, merge/split, full-text search, and printing — all without Adobe, accounts, or telemetry. --- ## What KillerPDF Does | Capability | Details | |---|---| | Rendering | High-quality PDFium rendering via Docnet.Core | | Annotation | Text boxes, freehand draw, highlight overlays | | Editing | Inline text editing with font matching | | Pages | Merge multiple PDFs, split selected pages, drag-and-drop reorder | | Signatures | Draw/save reusable signatures, click to place | | Search | Full-text search with highlighting, drag-select to copy | | Print | Annotations flattened into output | | Distribution | Single EXE, no runtime, no admin rights | --- ## Getting the Binary ```powershell # Download latest prebuilt release Invoke-WebRequest -Uri "https://github.com/SteveTheKiller/KillerPDF/releases/latest/download/KillerPDF.zip" -OutFile "KillerPDF.zip" Expand-Archive -Path "KillerPDF.zip" -DestinationPath ".\KillerPDF" .\KillerPDF\KillerPDF.exe ``` No installer, no admin rights required. Just unzip and run. --- ## Building from Source ### Requirements - Windows 10/11 x64 - .NET 8 SDK or later (to build; output targets .NET Framework 4.8) - Git ### Clone and Build ```powershell git clone https://github.com/SteveTheKiller/KillerPDF.git cd KillerPDF dotnet publish -c Release ``` Output lands in `bin/Release/net48/publish/`. The publish step produces: - `KillerPDF.exe` — single Costura-bundled executable - `KillerPDF-<version>-src.zip` — GPL3 corresponding source archive ### Project Structure ``` KillerPDF/ ├── App.xaml / App.xaml.cs # Application entry, theming ├── MainWindow.xaml / .cs # Primary WPF window, toolbar, page canvas ├── PdfDocument.cs # PDFium wrapper (Docnet.Core), load/save/render ├── PageViewModel.cs # Page data binding, annotation layer ├── AnnotationCanvas.cs # Custom Canvas for drawing/annotation ├── SignatureManager.cs # Save/load/place signatures ├── MergeWindow.xaml / .cs # Merge multiple PDFs UI ├── SplitWindow.xaml / .cs # Page selection and split UI ├── SearchPanel.xaml / .cs # Full-text search UI ├── PrintHelper.cs # Flatten annotations and print ├── Models/ │ ├── Annotation.cs # Base annotation model │ ├── TextBoxAnnotation.cs │ ├── DrawingAnnotation.cs │ └── HighlightAnnotation.cs └── Resources/ └── Icons/ # SVG/PNG toolbar icons ``` --- ## Key Dependencies ```xml <!-- KillerPDF.csproj (simplified) --> <Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <OutputType>WinExe</OutputType> <TargetFramework>net48</TargetFramework> <UseWPF>true</UseWPF> <AssemblyName>KillerPDF</AssemblyName> </PropertyGroup> <ItemGroup> <!-- PDFium rendering --> <PackageReference Include="Docnet.Core" Version="2.6.0" /> <!-- Single-EXE bundling --> <PackageReference Include="Costura.Fody" Version="5.7.0" /> <PackageReference Include="Fody" Version="6.8.0" /> </ItemGroup> </Project> ``` --- ## Core Patterns and Code Examples ### Opening and Rendering a PDF Page ```csharp using Docnet.Core; using Docnet.Core.Models; using System.Windows.Media.Imaging; using System.Runtime.InteropServices; public class PdfDocument : IDisposable { private IDocLib _docLib; private IDocReader _docReader; private readonly string _filePath; public int PageCount { get; private set; } public void Open(string filePath, string password = "") { _filePath = filePath; _docLib = DocLib.Instance; _docReader = string.IsNullOrEmpty(password) ? _docLib.GetDocReader(filePath, new PageDimensions(1080, 1920)) : _docLib.GetDocReader(filePath, password, new PageDimensions(1080, 1920)); PageCount = _docReader.GetPageCount(); } public BitmapSource RenderPage(int pageIndex, double dpi = 150) { using var pageReader = _docReader.GetPageReader(pageIndex); int width = pageReader.GetPageWidth(); int height = pageReader.GetPageHeight(); var rawBytes = pageReader.GetImage(); // BGRA byte array var bitmap = new WriteableBitmap(width, height, dpi, dpi, System.Windows.Media.PixelFormats.Bgra32, null); bitmap.WritePixels( new System.Windows.Int32Rect(0, 0, width, height), rawBytes, width * 4, 0); bitmap.Freeze(); return bitmap; } public string GetPageText(int pageIndex) { using var pageReader = _docReader.GetPageReader(pageIndex); return pageReader.GetText(); } public void Dispose() { _docReader?.Dispose(); _docLib?.Dispose(); } } ``` ### Annotation Model Hierarchy ```csharp // Models/Annotation.cs public abstract class Annotation { public Guid Id { get; } = Guid.NewGuid(); public int PageIndex { get; set; } public System.Windows.Rect Bounds { get; set; } public double Opacity { get; set; } = 1.0; public abstract UIElement ToUIElement(); public abstract void FlattenToPdfPage(PdfPage page); } // Models/TextBoxAnnotation.cs public class TextBoxAnnotation : Annotation { public string Text { get; set; } = ""; public string FontFamily { get; set; } = "Arial"; public double FontSize { get; set; } = 12; public System.Windows.Media.Color Color { get; set; } = System.Windows.Media.Colors.Black; public override UIElement ToUIElement() { var tb = new TextBox { Text = Text, FontFamily = new System.Windows.Media.FontFamily(FontFamily), FontSize = FontSize, Foreground = new System.Windows.Media.SolidColorBrush(Color), Background = System.Windows.Media.Brushes.Transparent, BorderThickness = new Thickness(0), AcceptsReturn = true, Width = Bounds.Width, Height = Bounds.Height, Opacity = Opacity, }; Canvas.SetLeft(tb, Bounds.X); Canvas.SetTop(tb, Bounds.Y); return tb; } public override void FlattenToPdfPage(PdfPage page) { // Write text at PDF coordinates using PdfSharp or iTextSharp // KillerPDF uses PDFium for reading and a lightweight writer for output } } // Models/HighlightAnnotation.cs public class HighlightAnnotation : Annotation { public System.Windows.Media.Color HighlightColor { get; set; } = System.Windows.Media.Colors.Yellow; public override UIElement ToUIElement() { var rect = new System.Windows.Shapes.Rectangle { Fill = new System.Windows.Media.SolidColorBrush( System.Windows.Media.Color.FromArgb( (byte)(Opacity * 128), HighlightColor.R, HighlightColor.G, HighlightColor.B)), Width = Bounds.Width, Height = Bounds.Height, }; Canvas.SetLeft(rect, Bounds.X); Canvas.SetTop(rect, Bounds.Y); return rect; } public override void FlattenToPdfPage(PdfPage page) { /* flatten */ } } ``` ### Freehand Drawing on the Annotation Canvas ```csharp // AnnotationCanvas.cs — custom WPF Canvas public class AnnotationCanvas : Canvas { private Polyline _currentStroke; private List<Point> _points = new(); public System.Windows.Media.Color PenColor { get; set; } = System.Windows.Media.Colors.Red; public double PenThickness { get; set; } = 2.0; public bool IsDrawingMode { get; set; } protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e) { if (!IsDrawingMode) return; _points.Clear(); _currentStroke = new Polyline { Stroke = new SolidColorBrush(PenColor), StrokeThickness = PenThickness, StrokeLineJoin = PenLineJoin.Round, StrokeStartLineCap = PenLineCap.Round, StrokeEndLineCap = PenLineCap.Round, }; Children.Add(_currentStroke); CaptureMouse(); AddPoint(e.GetPosition(this)); } protected override void OnMouseMove(MouseEventArgs e) { if (!IsDrawingMode || _currentStroke == null || e.LeftButton != MouseButtonState.Pressed) return; AddPoint(e.GetPosition(this)); } protected override void OnMouseLeftButtonUp(MouseButtonEventArgs e) { if (!IsDrawingMode || _currentStroke == null) return; ReleaseMouseCapture(); // Commit stroke as DrawingAnnotation var ann = new DrawingAnnotation { Points = _points.ToList(), Color = PenColor, Thickness = PenThickness }; AnnotationCommitted?.Invoke(this, ann); _currentStroke = null; } private void AddPoint(Point p) { _points.Add(p); _currentStroke.Points.Add(p); } public event EventHandler<DrawingAnnotation> AnnotationCommitted; } ``` ### Signature Manager ```csharp // SignatureManager.cs public class SignatureManager { private readonly string _sigDir; public SignatureManager() { // Signatures stored next to EXE — portable, no AppData _sigDir = Path.Combine( Path.GetDirectoryName( System.Reflection.Assembly.GetExecutingAssembly().Location)!, "Signatures"); Directory.CreateDirectory(_sigDir); } // Save ink strokes as PNG public void Save(string name, RenderTargetBitmap bitmap) { var encoder = new PngBitmapEncoder(); encoder.Frames.Add(BitmapFrame.Create(bitmap)); using var fs = File.OpenWrite(Path.Combine(_sigDir, name + ".png")); encoder.Save(fs); } // Load all saved signatures public IEnumerable<(string Name, BitmapImage Image)> LoadAll() { foreach (var file in Directory.EnumerateFiles(_sigDir, "*.png")) { var img = new BitmapImage(new Uri(file)); img.Freeze(); yield return (Path.GetFileNameWithoutExtension(file), img); } } // Place signature as Image UIElement on canvas public Image PlaceSignature(BitmapImage sigImage, Point position, double scale = 1.0) { var img = new Image { Source = sigImage, Width = sigImage.PixelWidth * scale, Height = sigImage.PixelHeight * scale, Opacity = 0.9, }; Canvas.SetLeft(img, position.X); Canvas.SetTop(img, position.Y); return img; } } ``` ### Merging PDFs ```csharp // MergeWindow.xaml.cs (core merge logic) public static void MergePdfs(IEnumerable<string> inputPaths, string outputPath) { // KillerPDF uses PDFium C++ API via P/Invoke or a lightweight wrapper // Conceptual pattern using PdfSharp (or equivalent internal helper): using var output = new PdfDocument(); // PdfSharp or internal writer foreach (var path in inputPaths) { using var input = PdfReader.Open(path, PdfDocumentOpenMode.Import); for (int i = 0; i < input.PageCount; i++) output.AddPage(input.Pages[i]); } output.Save(outputPath); } ``` ### Splitting Pages ```csharp public static void SplitPages(string inputPath, IEnumerable<int> pageIndices, string outputPath) { using var input = PdfReader.Open(inputPath, PdfDocumentOpenMode.Import); using var output = new PdfDocument(); foreach (var idx in pageIndices) output.AddPage(input.Pages[idx]); output.Save(outputPath); } ``` ### Full-Text Search ```csharp // SearchPanel.xaml.cs public List<(int PageIndex, System.Windows.Rect Rect)> Search( string query, PdfDocument doc) { var results = new List<(int, System.Windows.Rect)>(); var docLib = DocLib.Instance; using var reader = docLib.GetDocReader(doc.FilePath, new PageDimensions(1080, 1920)); for (int i = 0; i < reader.GetPageCount(); i++) { using var page = reader.GetPageReader(i); var text = page.GetText(); if (!text.Contains(query, StringComparison.OrdinalIgnoreCase)) continue; // Get character bounding boxes for highlighting var chars = page.GetCharacters(); // Match positions and build highlight Rects // (KillerPDF uses character-level positions from PDFium) int idx = text.IndexOf(query, StringComparison.OrdinalIgnoreCase); while (idx >= 0 && idx + query.Length <= chars.Count) { var first = chars[idx]; var last = chars[idx + query.Length - 1]; var rect = new System.Windows.Rect( first.Box.Left, first.Box.Top, last.Box.Right - first.Box.Left, last.Box.Bottom - first.Box.Top); results.Add((i, rect)); idx = text.IndexOf(query, idx + 1, StringComparison.OrdinalIgnoreCase); } } return results; } ``` ### Printing with Flattened Annotations ```csharp // PrintHelper.cs public static void PrintDocument(BitmapSource[] renderedPages, string docTitle) { var pd = new PrintDialog(); if (pd.ShowDialog() != true) return; var doc = new FixedDocument(); foreach (var page in renderedPages) { var pageContent = new PageContent(); var fixedPage = new FixedPage { Width = pd.PrintableAreaWidth, Height = pd.PrintableAreaHeight, }; var img = new Image { Source = page, Width = pd.PrintableAreaWidth, Height = pd.PrintableAreaHeight, Stretch = System.Windows.Media.Stretch.Uniform, }; fixedPage.Children.Add(img); ((IAddChild)pageContent).AddChild(fixedPage); doc.Pages.Add(pageContent); } var xpsWriter = PrintQueue.CreateXpsDocumentWriter( pd.PrintQueue); xpsWriter.Write(doc); } // Flatten annotations: render page + annotation canvas to BitmapSource public static BitmapSource FlattenPage(BitmapSource pdfPageBitmap, AnnotationCanvas canvas, int width, int height) { var visual = new DrawingVisual(); using (var ctx = visual.RenderOpen()) { ctx.DrawImage(pdfPageBitmap,