Writing NFC Tags in .NET

I first added NFC code to 32feet.NET back in 2020. However, as other priorities came along it never got fully polished and released on NuGet. This year I finally got around to it and updated the code for .NET 8.0 as it had originally targeted Xamarin Forms.

InTheHand.Nfc is available on NuGet and follows the API model of WebNFC – it supports reading and writing NDEF tags as this is the most widely used format for providing Urls, text and other custom data types. Although the original Windows codebase is still there it is largely untouched and untested because there is no definitive NFC hardware for Windows and the external Sony reader I had been using is no longer supported. I was able to install the drivers and get it running but I’m not currently able to read tags through the API. Since iOS and Android are more important platforms for this functionality I’ve not spent any more time on the Windows implementation yet.

There is a sample .NET MAUI app to demonstrate how to use the library. However it should work on any other .NET based platform (Uno, Avalonia etc). There are some platform specific setup items to observe – NFC reading requires permission on both Android and iOS. For iOS you must also add the NFC Reading capability to your app id.

The code is quite simple. It’s all async and uses Events for detecting tags. You can either pass a cancellation token to control when to stop scanning or if you don’t it will automatically stop after the first tag is scanned.

Hopefully you’ll find this useful for adding NFC reading/writing to your .NET apps. I do want to re-enable the Windows functionality, and make sure everything described in the sample is also documented in the Wiki. The only missing functionality from WebNFC is the ability to make a tag read-only; if there is a demand I could look at adding this too.