AvaloniaControls.SpreadsheetEditor

An Excel-like spreadsheet editor control for Avalonia UI, published as the NuGet package Devolutions.AvaloniaControls.SpreadsheetEditor.

Important

This control requires a commercial Avalonia UI (Accelerate) license. It builds on the paid Avalonia.Controls.RichTextEditor and Avalonia.Controls.Charts packages, which need a valid license key at build time. The source is MIT-licensed, but you cannot build or run the control (or an app that consumes it) without your own Avalonia license. See Requirements.

It uses a custom rendering grid (not the Avalonia DataGrid) so cells can merge and host rich content:

• Custom grid with cell merging, frozen headers, drag-to-select, and infinite rows/columns.
• Rich in-cell editing (bold / italic / underline / strikethrough, fonts, colors, alignment).
• A hand-rolled = formula engine (arithmetic, ranges, SUM/AVERAGE/IF/…, named ranges, live recalc).
• Charts, multi-sheet tabs, undo/redo, clipboard, a symbol picker, and printing (cross-platform PDF export, a native Windows print dialog, and lpr/CUPS on Linux/macOS).
• An integration API modeled on Avalonia's RichTextEditor (IsReadOnly, Undo/Redo, CanUndo/CanRedo, SelectAll, SelectedRange, and ContentChanged / SelectionChanged / IsReadOnlyChanged events).

Repository layout

Path	Description
SpreadsheetEditor.Controls/	The reusable control library (the NuGet package).
SampleApp/	A sample desktop host app demonstrating the control (open/save .xlsx, print, …).
Common.props, Directory.Build.props	Shared build settings, dependency versions, and license handling.

Requirements

This control depends on the commercial Avalonia Accelerate packages (Avalonia.Controls.RichTextEditor, Avalonia.Controls.Charts). Building it — and any app that consumes it — requires a valid Avalonia UI license key. See https://avaloniaui.net/.

Building locally

Provide your Avalonia license key via a git-ignored .env file at the repository root:

AVALONIA_LICENSE_KEY=your-key-here

(Alternatively set an AVALONIA_LICENSE_KEY environment variable.) Then:

dotnet build SpreadSheetEditor.sln
dotnet run --project SampleApp        # launch the sample app
dotnet pack SpreadsheetEditor.Controls -c Release   # build the NuGet package

Using the control

Add the required theme includes to your App.axaml (alongside FluentTheme):

<Application.Styles>
    <FluentTheme />
    <StyleInclude Source="avares://Avalonia.Controls.RichTextEditor/Themes/Default.axaml" />
    <StyleInclude Source="avares://Avalonia.Controls.Charts/Themes/Default.axaml" />
</Application.Styles>

Then place the control:

xmlns:se="clr-namespace:SpreadsheetEditor.Controls;assembly=SpreadsheetEditor.Controls"
...
<se:SpreadsheetEditor x:Name="Editor" />

License

MIT — see LICENSE.