Important
To ensure the long-term sustainability of this project, a monthly maintenance fee has been introduced. This fee is required to be paid by all organizations or users of any library from this project who generate revenue. You can pay the fee via GitHub Sponsors.
To enact this, an EULA on binary releases is added to the repo and nuget packages since 2.8.0 that requires payment of the maintenance fee.
For more information on who must pay the fee and other frequently asked questions, please see the Open Source Maintenance Fee organisation page.
This project is the .NET version of Apache POI project. With NPOI, you can read/write Office 2003/2007 files very easily.
Thank you for all the sponsors. Here is the sponsors list
a. It's totally free to startups, freelancers, and hobbyists (whose annual revenue is less than $10,000 USD)
b. Cover most features of Excel (cell style, data format, formula and so on)
c. Supported formats: xls, xlsx, docx.
d. Designed to be interface-oriented (take a look at NPOI.SS namespace)
e. Support not only export but also import
f. Real successful cases all over the world
g. Works on both Windows and Linux
The initial NPOI.XSLF.UserModel API supports creating an empty transitional
.pptx presentation, adding blank slides, and saving and reopening the package:
using NPOI.XSLF.UserModel;
using System.IO;
using var presentation = new XMLSlideShow();
presentation.CreateSlide();
presentation.CreateSlide();
using var output = File.Create("blank-slides.pptx");
presentation.Write(output);Use new XMLSlideShow(inputStream) or new XMLSlideShow(opcPackage) to open an
existing presentation, and GetSlides() to access slides in presentation order.
Closing the presentation closes its underlying OPC package. As with the other
OOXML APIs, save to a different file when opening a package from a file path.
The foundation follows the existing OOXML layering: partial PresentationML data
models live in OpenXmlFormats/Presentation, while XMLSlideShow, XSLFSlide,
XSLFRelation, and XSLFFactory live in ooxml/XSLF/UserModel. Packaging uses the
existing OPC implementation. Slides, masters, and layouts share XSLFSheet.
GetSlideMasters() and GetSlideLayouts() follow their XML reference-list order.
XSLFTheme exposes read-only theme metadata using the existing DrawingML model.
Unchanged master, layout, and theme parts retain their original bytes; unmodeled
content remains intact when supported sheet models are saved.
Opaque extension children retain their order relative to modeled sheet content,
including extensions preceding common slide data in masters and layouts.
Use a layout from the same presentation to create a slide explicitly:
var master = presentation.GetSlideMasters()[0];
var layout = master.GetLayout("Blank");
if (layout == null)
throw new InvalidOperationException("This master has no layout named Blank.");
var slide = presentation.CreateSlide(layout);
var theme = slide.GetTheme(); // May be null when the master has no theme.Layouts expose Name and the PresentationML Type string. Slides expose
GetSlideLayout(), GetSlideMaster(), and GetTheme(). The layout must be listed
by a referenced master in the same presentation. Attaching a layout does not
yet copy placeholder shapes or resolve inherited text formatting. Theme editing
is not supported.
This is a foundation, not full PowerPoint support. Parameterless slide creation requires an existing blank layout (included in newly created presentations). The layout overload can select other layout types. Existing slide content and unsupported related parts are retained, but high-level text boxes, pictures, tables, charts, notes, rendering, and animation APIs are not yet implemented. Strict OOXML and macro-enabled presentation formats are not supported.
.NET 8, .NET 10
.NET Standard 2.1 (.NET Core 3.x, .NET 5, .NET 6)
.NET Standard 2.0 (.NET Core 2.x)
.NET Framework 4.0 and above
For detailed contributors list, you are read here
