Plugin.Maui.KeyListener

Plugin.Maui.KeyListener provides KeyboardBehavior to listen for keyboard up (pressed) and down (released) events on any view in a .NET MAUI application. This is useful in situations where a KeyboardAccelerator isn't suitable.

Current status: I've got macOS working, and Windows via global window events. Android and iOS need some love.

Install Plugin

Available on NuGet.

Install with the dotnet CLI: dotnet add package Plugin.Maui.KeyListener, or through the NuGet Package Manager in Visual Studio.

Supported Platforms

Platform	Minimum Version Supported
iOS	11+
macOS	10.15+
Android	5.0 (API 21)
Windows	11 and 10 version 1809+

Accessibility Considerations

Windows

Implementing KeyboardBehavior to manage navigation and interaction on Windows enhances accessibility because Windows accessibility features are tightly integrated with keyboard navigation. This allows users who rely on keyboard input rather than mouse interactions to navigate your application effectively.

Mac

Using KeyboardBehavior on macOS improves navigation for users who have enabled basic keyboard navigation features. However, it provides no benefits for users utilizing Full Keyboard Access mode or VoiceOver screen reader navigation. For comprehensive accessibility support on Mac (and Windows), it's recommended to implement the SemanticOrderView from the MAUI Community Toolkit alongside KeyboardBehavior.

API Usage

Plugin.Maui.KeyListener provides the Feature class that has a single property Property that you can get or set.

You can either use it as a static class, e.g.: Feature.Default.Property = 1 or with dependency injection: builder.Services.AddSingleton<IFeature>(Feature.Default);

Regisgtration

Before you can start using KeyboardBehavior, you need to register to use it in your MauiProgram:

public static MauiApp CreateMauiApp()
{
    var builder = MauiApp.CreateBuilder();
    builder
        .UseMauiApp<App>()
        .UseKeyListener();    

    return builder.Build();
}

Listening

Add the behavior to the visual element where you want to listen for keyboard events. These events will bubble up no matter where you have focus.

public class MainPage : ContentPage
{
    KeyboardBehavior keyboardBehavior = new ();
    
    protected override void OnNavigatedTo(NavigatedToEventArgs args)
	{
		keyboardBehavior.KeyDown += OnKeyDown;
		keyboardBehavior.KeyUp += OnKeyUp;
		this.Behaviors.Add(keyboardBehavior);

		base.OnNavigatedTo(args);
	}

	protected override void OnNavigatedFrom(NavigatedFromEventArgs args)
	{
        keyboardBehavior.KeyDown -= OnKeyDown;
		keyboardBehavior.KeyUp -= OnKeyUp;
		this.Behaviors.Remove(keyboardBehavior);

		base.OnNavigatedFrom(args);
	}

    void OnKeyUp(object sender, KeyPressedEventArgs args)
    {
        // do something
    }

    void OnKeyDown(object sender, KeyPressedEventArgs args)
    {
        // do something
    }
}

Sample

There is a sample project here in the repository. I've also built a little game GuessWord that uses this plugin.

Acknowledgements

This is almost all code from @pureween, with some additions by @davidortinau and contributors! <3