QuoteOriginally posted by: fulmerspotQuoteOriginally posted by: GovertQuoteOriginally posted by: fulmerspotI did play with this before deciding to use C# and therefore ExcelDNA on my current project. I suspect it will be a while yet before Microsoft can demise the C API but if the [UdfClass] interface becomes available on the next version then I'd use that to keep a single common API across local and hosted Excel.@fulmerspot:The managed UDFs for Excel Services (the version of Excel online that runs in SharePoint) were introduced 10 years ago, and though it seems to still be supported, the feature has not been updated or incorporated in the Excel client in the last decade through four Excel client versions - 2007 to 2016. The Excel C API has had significant updates in these versions, including large sheet and long string support, multi-threaded functions and native async functions.In fact, you are the first person I have heard of that uses the managed UDFs on Excel Services.I would love to get in touch, especially as you also use Excel-DNA.When the managed UDFs for Excel Services were first introduced, I added an option in Excel-DNA that allows you to expose the managed UDF binaries to the Excel client without modification, recompiling or adding any dependencies. You should be able to take exactly the same binary that runs on the server, and with a .dna that gives the path file and a copy of ExcelDna.xll you can run the same UDFs on the Excel client. However, I have never been able to test this, having never found or seen such a managed UDF library. I'd be very happy to test and check that this feature works right, if that would have any value to you.Without needing your server-side UDF library to add any references, you can also mark up your functions with [Description] attributes, and both the function wizard and new in-sheet IntelliSense feature (
https://github.com/Excel-DNA/IntelliSense) should expose those function and argument descriptions.-GovertExcel-DNA - Free and easy .NET for ExcelHi GovertFrom what I see from Microsoft, the Excel Services which have been available when running Excel online through SharePoint have been expanded - for Office Web Apps (OWA) there are a number of new addin types, this is where I get the Excel Services in Office Online info: Configure UDFs in Excel Online in Office Online Server Preview I don't yet have a full dev setup of SharePoint and OWA to confirm all this. Herr KartoffelKopfYes - that link is exactly the managed UDF support for Excel Services that I'm referring to.It was introduced in 2006. Shahar Prish wrote a whole series of blog posts: How UDFs work in Excel Services.-GovertExcel-DNA - Free and easy .NET for Excel