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Aspose.Slides FOSS for .NET

Create, read, and edit PowerPoint presentations from .NET — free and open-source, no Office dependency required.

Aspose.Slides FOSS for .NET Aspose.Slides FOSS
for .NET

Documentation GitHub

Open-Source .NET Library for PowerPoint Presentations

Aspose.Slides FOSS for .NET is a MIT-licensed pure-C# library for working with PowerPoint .pptx files. Add a single NuGet package and immediately start creating, reading, and editing presentations without installing Microsoft Office or any proprietary runtime.

The library exposes a Presentation API built around Presentation, Slide, Shape, TextFrame, Paragraph, and Portion, the conceptual model used by PowerPoint itself. Add and remove slides, insert AutoShapes, Tables, and Connectors, format text at character level with bold, italic, font size and color, apply solid or gradient fills, and add visual effects (shadow, glow, blur, reflection).

The IDisposable pattern ensures reliable resource cleanup: always wrap a Presentation in a using statement. Unknown XML parts encountered during load are preserved verbatim on save, so round-tripping never destroys content the library does not yet understand. The library requires .NET 9.0 or later and has no native extensions to compile.

Presentation and Slide API

  • Create and open PPTX: Create new presentations or open existing .pptx files via new Presentation() or new Presentation(file).
  • Add and remove slides: Programmatically manage the SlideCollection with AddClone(), AddEmptySlide(), Remove(), and RemoveAt().
  • AutoShapes: Insert rectangles, ellipses, lines, and other ShapeType geometries via AddAutoShape().
  • Tables and Connectors: Add structured table shapes and connector lines between shapes via AddConnector().
  • Speaker notes: Read and write per-slide speaker notes through NotesSlideManager.
  • Threaded comments: Access slide-level comment threads with GetSlideComments().

Where Aspose.Slides FOSS Can Be Used

  • Report generation: Build branded slide decks from data sources without Office.
  • Template automation: Fill PPTX templates with dynamic content in CI/CD pipelines.
  • Content migration: Read existing presentations and restructure or re-style slides.
  • Serverless backends: Process PPTX files inside Docker containers or Azure Functions.
  • Batch processing: Apply uniform formatting changes across large slide deck libraries.

Text Formatting and Visual Effects

  • Character-level formatting: Apply bold, italic, font size, and color to individual Portion objects via PortionFormat.
  • Solid and gradient fills: Set shape fill to a solid color or multi-stop linear gradient using FillFormat and FillType.
  • Shadow and glow effects: Apply outer shadow, glow, blur, and reflection to any shape via EffectFormat.
  • Paragraph alignment: Set left, center, right, or justify alignment per paragraph using ParagraphFormat.Alignment.
  • Round-trip safe: Unknown XML parts are preserved verbatim on re-save.

Developer Experience

Aspose.Slides FOSS installs with a single dotnet add package Aspose.Slides.Foss command. The library is pure C# with no native extensions to compile and no system packages to install.

The API mirrors PowerPoint’s own object model (Presentation, Slide, Shape, TextFrame, Paragraph, Portion), so anyone familiar with the PowerPoint object model can use the library immediately. It is MIT-licensed, open-source on GitHub, and requires .NET 9.0 or later.

Create a Presentation and Add a Shape

Use a using statement to ensure the Presentation is always disposed and resources are freed. AddAutoShape() takes a ShapeType enum, then x/y position and width/height in points — the shape’s TextFrame.Text property sets the label in one line.

dotnet add package Aspose.Slides.Foss

using Aspose.Slides.Foss;

using var prs = new Presentation();
var slide = prs.Slides[0];

// Add a rectangle AutoShape
var shape = slide.Shapes.AddAutoShape(
    ShapeType.Rectangle, 50, 50, 400, 150
);
shape.TextFrame.Text = "Hello, Aspose.Slides!";

prs.Save("output.pptx", SaveFormat.Pptx);

Format Text and Apply a Fill Effect

Text formatting works at the Portion level — the smallest unit of a run of characters. Open the saved file, navigate to the first portion of the first paragraph, and set font properties directly. Shape fill is independent: set FillType to Solid and assign a color to SolidFillColor.Color.

using Aspose.Slides.Foss;

using var prs = new Presentation("output.pptx");
var shape = prs.Slides[0].Shapes[0];
var portion = shape.TextFrame.Paragraphs[0].Portions[0];

// Bold, 18pt, dark-blue text
portion.PortionFormat.FontBold = NullableBool.True;
portion.PortionFormat.FontHeight = 18;
portion.PortionFormat.FillFormat.SolidFillColor.Color =
    Color.FromArgb(255, 0, 0, 139);

// Solid background fill on the shape
shape.FillFormat.FillType = FillType.Solid;
shape.FillFormat.SolidFillColor.Color =
    Color.FromArgb(255, 240, 248, 255);

prs.Save("formatted.pptx", SaveFormat.Pptx);

Frequently Asked Questions

What is Aspose.Slides FOSS for .NET?

It is a free, MIT-licensed pure-C# library for creating, reading, and editing PowerPoint .pptx presentations without requiring Microsoft Office.

Which file formats are supported?

PPTX is the supported read/write format. Export to PDF, HTML, SVG, or images is not available in this edition.

Does it require Microsoft Office or PowerPoint?

No. Aspose.Slides FOSS is a pure-C# library with no dependency on Microsoft Office, COM automation, or any proprietary runtime.

How do I install it?

Run dotnet add package Aspose.Slides.Foss. The library requires .NET 9.0 or later. There are no native extensions to compile.

Can I apply visual effects like shadow and glow?

Yes. The library supports outer shadow, glow, blur, and reflection effects on any shape object via the EffectFormat API.

Is the IDisposable pattern recommended?

Yes. Always wrap a Presentation in a using statement (using var prs = new Presentation();) to ensure reliable resource cleanup.

Will round-tripping a PPTX destroy unknown content?

No. Unknown XML parts encountered during load are preserved verbatim on save, so content the library does not yet understand is never lost.

Where can I find the source code?

The library is MIT-licensed and hosted on GitHub. Bug reports and pull requests are welcome.

  

Support and Learning Resources

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