ClosedXML

ClosedXML is a pretty handy .NET library for anyone who wants to work with Excel files. Whether you need to read, tweak, or write Excel documents, this tool has got your back! It was made to simplify the tricky parts of the OpenXML API, making it easier for developers like us.

Compatibility with Excel Versions

This library plays well with older versions of Excel from 2007 and keeps up with the latest releases too. The best part? You don’t even need to have Excel installed on your computer to use it. Just imagine being able to handle all those spreadsheets without any extra software!

Important Note on Thread Safety

Now, a little heads up: ClosedXML isn’t thread-safe. This means if you try running multiple operations at once, things might not go as planned. To avoid any hiccups, it's a good idea to check out the documentation. It’s packed with useful tips and answers for common questions.

Common Issues and Solutions

A common issue users face is when text that looks like numbers gets converted into actual numbers. This happens because when you set a cell's value, it uses the .ToString() method and decides how to interpret that value—whether it's a number, date, boolean, or text.

If you want to keep a number as text instead of converting it automatically, there are a couple of easy fixes. You can change the cell's data type to text by setting its format to “@” before entering the value. Or you can start the number with a single quote like this: cell.Value = "'123". This little trick helps keep everything just how you want it!