Android deep-links and NFC

Deep-linking is the ability to define a Url which will direct the user straight to a specific feature of your app. On Android these are called App-links, for iOS they tend to be called Universal links. These can be an app-specific uri scheme or you can, with the right configuration on your web server, link a web domain so that you can redirect web links to the equivalent page in your app. I’m going to be working with the first type here.

.NET MAUI allows you to support deep-linking on both platforms once you’ve set up the necessary handler code in each native project. This passes the received Uri to the Application class so you can handle parsing the Uri and navigating in a single place. I’m not going to go over this process because it is described in the MAUI documented for Android and iOS.

This allows your app to be launched from a browser, QR Code, or another app. However the default experience on Android for an NFC tag results in a “New tag collected” dialog which asks you if you want to follow the link. Luckily, there is a way around this. You have to specify an additional action in your IntentFilter. Alongside Intent.ActionView you can add NfcAdapter.ActionNdefDiscovered. With this added your app is correctly registered to receive intents from Uri tags and will launch immediately when presented with your specific app link.

[IntentFilter(new [] { Intent.ActionView, Android.Nfc.NfcAdapter.ActionNdefDiscovered },
Categories = new [] { Intent.CategoryDefault, Intent.CategoryBrowsable },
DataScheme = "yourscheme")]

The great thing about implementing this is you may already be using deep-linking and you can support links from NFC tags without actually having to implement any NFC reading code within your app. You can have a consistent mechanism for working with links from a variety of sources.