office-ribbonx-editor VS ClosedXML

Have you tried the Office Ribbon Editor? It makes the XML portion very easy to manage. There might be a weird issue with the way you're currently doing it causing the xml to be removed from the file.

By using ribbonX (find it here: https://github.com/fernandreu/office-ribbonx-editor) you can create custom toolbars based on XML, however this can be difficult.

And rather than handcoding the RibbonXML, you'll want a copy of the free Office RibbonX Editor: https://github.com/fernandreu/office-ribbonx-editor

However, I've always just used this FOSS editor. It's a standalone editor, no need for admin rights, and best of all makes editing the file for the custom tab super easy along with verifying your xml is formatted correctly for the change.

I create custom tabs using the new fabric custom UI API and office ribbonX editor, which is open source and makes the life so much easier (I believe this may be the tool you're using), if not you should def give it a try. The tool comes in a pre-compiled version that is compressed. No need for admin rights or anything.

I have a workbook with a custom ribbon (added via XML using the Office RibbonX Editor so that the custom ribbon stays with the workbook). In the Ribbon, I have a few checkboxes true/false, that are linked to cells on a worksheet.

Office RibbonX Editor - an opensource alternative to Visual Studio (expressly for the purpose of creating the customUI file needed to create a custom Ribbon, not an IDE). The README has good information, and links to further resources for creating an Add-in.

It's also country specific.

I work on Excel library and the text to number/date feature was one of less fun things to implement at least semi-correctly.

I remember my comment on the PR back then:

https://github.com/ClosedXML/ClosedXML/pull/1899

Once installed, you can start using ClosedXML directly in your project. Go through their wiki for some sample codes based on what you are trying to achieve in your app.

There are alternatives to requiring opening the full Excel application and its resource overhead. Especially given you're simply reading, sorting, and writing. One of the most popular is CloseXML which you add via a NuGet package.

Time to dig into those open xml docs. Honestly it’s not that bad once you get your bearings. ClosedXML offers a somewhat thin wrapper as well. I’ve used these with great success but they are quite low level.

ClosedXML is an open wrapper around OOXML.

It's open-source: https://github.com/ClosedXML/ClosedXML