Excel Native AOT

Proof-of-concept of using .NET Native AOT (ahead-of-time) compilation features to build Excel XLL add-ins.

Features

• 100% C# with unmanaged/native methods directly callable by Excel (the C/C++ projects are used just for debugging)
• Access to the C/XLL (through UnmanagedCallersOnly) and COM APIs (through GeneratedComInterface)
• No need for .NET runtimes for deployment
• Better performance and/or hot reloading (possibly?)

Instructions

• Clone the project
• Set ExcelNativeDebugger as the starting project if it's not already
• Open TestSheet.xlsx
• Tweak settings/paths if necessary

Test machine

• Visual Studio 2022 17.8.0 Preview 1.0
• .NET 8.0.100-preview.7.23376.3
• Microsoft® Excel® 365 (Version 2307) 64-bit
• Windows 11 Home 22H2

Todo

• Add all possible XlOper types
• Use code generation to wrap marshalling of variables and method generation

Credits

• Excel-DNA / @govert
• xlOil / @cunnane
• Native AOT samples
• Tutorial for building XLL's starting by the SDK
• Bing Chat, StackOverflow, etc