ClosedXML VS Sylvan

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

A while back I needed to process CSV with millions of records in a timescale of seconds. Sylvan Data was the best fit in terms of speed and memory efficiency. It might help you. https://github.com/MarkPflug/Sylvan

I maintain a couple libraries that aim to provide similar functionality to MTD: Sylvan.Data and Sylvan.Data.Csv.

Here is a simple, complete gist showing how to turn a DbDataReader into an HTML table. The WriteHtmlTable extension method can be used with any ADO.NET compatible driver, which the Sylvan.Data.Excel and Sylvan.Data.Csv libraries both support.

I maintain a couple libraries that can help with reading the data files: Sylvan.Data.Csv and Sylvan.Data.Excel. I see no reason to not allow users to provide whichever format is convenient for them.

I maintain a CSV library, Sylvan.Data.Csv, that shouldn't have any issue parsing this. You'll need to explicitly specify that space (' ') is the delimiter.

Here is a some sample code of how to echo the contents of an Excel spreadsheet as CSV to the client browser using my libraries Sylvan.Data.Excel and Sylvan.Data.Csv:

``` For reference, my implementation is here.

I maintain a couple libraries that should make this quite easy: Sylvan.Data.Csv, and Sylvan.Data.Excel. They are both open-source and MIT licensed. They are also both fastest-in-class at their particular tast.

Personally, I'd recommend Sylvan.Data.Csv, but being the author I'm probably a bit biased. Here is some CSV performance analysis that Joel Verhagen did for .NET libraries recently.