Aspose.Slides.FOSS 26.9.0

Aspose.Slides FOSS for .NET

A free, MIT-licensed library for creating, reading and editing PowerPoint .pptx presentations from .NET. It builds the Office Open XML package itself, so it has no package dependencies and needs neither PowerPoint nor COM interop, and it runs on Windows, Linux and macOS.

It is a focused library rather than a small one. Everything below is verified by opening the file it produced and asserting on the XML inside — never by asking the library to read its own output back.

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Install

dotnet add package Aspose.Slides.FOSS

Targets net8.0 and net10.0.

Quick start

using Aspose.Slides.Foss;
using Aspose.Slides.Foss.Export;

using var presentation = new Presentation();

ISlide slide = presentation.Slides[0];
IAutoShape shape = slide.Shapes!.AddAutoShape(ShapeType.Rectangle, 50, 50, 400, 100);
ITextFrame text = shape.AddTextFrame("Hello from Aspose.Slides FOSS")!;
text.Paragraphs[0].Portions[0].PortionFormat!.FontBold = NullableBool.True;

presentation.Save("hello.pptx", SaveFormat.Pptx);

The namespace is Aspose.Slides.Foss — the package identifier is capitalised FOSS, the code is not. The ! operators are needed rather than decorative: ISlide.Shapes and IAutoShape.AddTextFrame are declared nullable, and a project with nullable reference types enabled warns without them.

What it does

• Presentations — create, open a file or a stream, save to a file or a stream.
• Slides — add, remove, clone, hide. Sections, including reordering slides with them.
• Masters and layouts — enumerate them, and clone a master.
• Shapes — AutoShapes (187 of the 189 ShapeType values), connectors with connection sites, tables with cell merging, picture frames.
• Text — text frames, paragraphs and portions; character and paragraph formatting; alignment.
• Appearance — solid, gradient, pattern and picture fills; line formatting; all eight visual effects; 3-D formatting.
• Pictures — added from a byte[] or a Stream.
• Notes and comments — speaker notes, and classic comments with their authors.
• Round-trip — XML parts the library does not model are preserved verbatim. On the 46-part PowerPoint deck in the test data, 46 parts go in and 46 come out, none dropped and none added; 42 are byte-identical and 4 are rewritten ([Content_Types].xml, docProps/app.xml, docProps/core.xml, ppt/presentation.xml).

What it does not do

Stated plainly, because a library that fails silently is worse than one that says no. Every entry below raises rather than producing a file that looks right and is not.

• No rendering or conversion of any kind. No PDF, HTML, SVG, image or text export. SaveFormat declares 21 values; three are written — Pptx, Ppsx, Potx — and the other 18 raise NotSupportedException naming the format and the three that work.
• No macro-enabled formats. Pptm, Ppsm and Potm need a VBA project part this library does not write, and they raise for that reason specifically.
• No charts, no SmartArt, no OLE objects, no video or audio frames, no group shapes.
• No animations and no slide transitions.
• No hyperlinks. IHyperlinkContainer is declared and several types implement it, but the interface has no members — implementing it gives you nothing.
• No slide backgrounds, no themes, and no slide size control. A new presentation is 4:3 and cannot be changed.
• No threaded comments. A reply is accepted by the object model and no ppt/threadedComments/ part is written, so it does not survive a save. Classic comments do.
• No encryption, protection, digital signatures or mathematical text.
• IImageCollection.AddImage has no overload taking a path — read the bytes or open the stream yourself.

When you want the commercial product

This library is not a drop-in replacement for Aspose.Slides for .NET, and it is not trying to be. If you need PDF or image rendering, charts, animations, the other presentation formats, or a support commitment, that is the product to use. If you need to build and read .pptx packages under a permissive licence with nothing else in your dependency tree, this one is complete for that.

Licence and support

MIT. The full text is packed alongside this file.

Questions and bug reports are welcome on the issue tracker or on the free support forum. A report that names the version and attaches the file PowerPoint would not open is one that can be acted on.

Product page | Documentation | API reference | Source | Issues | Free support