Each platform should provide a notification whenever the user changes the device's location or language. For example, iOS sends out a NSCurrentLocaleDidChangeNotification that includes a language property.

You'll need to register for and observe the platform notifications using Xamarin.Forms local notifications procedure, which notes (bolding and italics added):

Each platform handles the creation, display, and consumption of local notifications differently. This article explains how to create a cross-platform abstraction to send, schedule, and receive local notifications with Xamarin.Forms.

• Create a cross-platform interface

• Consume the interface in Xamarin Forms

• Create and handle an Android interface implementation

• Create and handle an iOS interface implementation

There are a number of tutorials on how to do this. Search on xamarin forms local notification consume tutorial to find some. Note the term local. You're not wanting push notifications - that's something else.

To perform this task more simply, you might be able to use a plugin, such as edsnider/localnotificationsplugin on GitHub. You might find more by replacing the terms consume tutorial with plugin in your search.

Clarification:

• local notifications occur intra-device, ie, the device or apps send notifications internally to be consumed by apps on the device.
• push notifications occur when a request is made to an external service, such as Azure. That service would then broadcast a corresponding notification to the appropriate device(s).

Please try

Java.Util.Locale currentLanguage = this.Resources.Configuration.Locales.Get (0);

I am using this call in Xamarin Android and it works fine for me. "this" is in class Android.App.Activity.