Shaunebu.MAUI.LifecycleManager 📗

A lightweight, cross-platform application lifecycle manager for .NET MAUI. This library provides foreground/background lifecycle events across Android, iOS, and Windows, allowing developers to react to app state changes in a consistent way. It abstracts platform differences and exposes a simple event-driven API.

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Features

• Cross-platform lifecycle awareness: Handles foreground and background transitions on Android, iOS, and Windows.

• Event-driven API: Subscribe to OnEnterForeground and OnEnterBackground.

• Simple initialization: Minimal setup in App.xaml.cs.

• Thread-safe callbacks: All events are marshaled appropriately to ensure safe UI interactions.

• No external dependencies: Pure MAUI library.

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Installation

Install via NuGet Package:

Install-Package Shaunebu.MAUI.LifecycleManager

Add the namespace in your MAUI project:

using Shaunebu.MAUI.LifecycleManager;

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Initialization

Initialize the library in App.xaml.cs:

public partial class App : Application { public App() { InitializeComponent(); // 1️⃣ Create lifecycle manager var lifecycle = LifecycleManager.Current; // 2️⃣ Subscribe to lifecycle events lifecycle.OnEnterForeground += () => { Console.WriteLine("✅ App entered foreground"); }; lifecycle.OnEnterBackground += () => { Console.WriteLine("🌙 App entered background"); }; // 3️⃣ Initialize (wires platform-specific events) lifecycle.Initialize(); } protected override Window CreateWindow(IActivationState? activationState) { return new Window(new AppShell()); } }

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API Reference

Class: LifecycleManager

Property / Event	Type	Description
Current	LifecycleManager	Singleton instance of the lifecycle manager.
OnEnterForeground	Action	Triggered when the app enters the foreground.
OnEnterBackground	Action	Triggered when the app enters the background.

Methods

Method	Parameters	Description
Initialize()	None	Subscribes platform-specific lifecycle events and starts tracking.
InvokeForeground()	None	Manually trigger foreground callbacks.
InvokeBackground()	None	Manually trigger background callbacks.

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Platform Behavior

Platform	Foreground Detection	Background Detection	Notes
Android	OnResume / OnStart	OnPause	Works in activities lifecycle; supports multiple windows.
iOS	WillEnterForeground	DidEnterBackground	Requires partial class on AppDelegate.
Windows	Window.Activated	Window.VisibilityChanged	Background detection is approximate (visibility-based).

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Usage Example

var lifecycle = LifecycleManager.Current; lifecycle.OnEnterForeground += () => { // Refresh UI or reconnect services Console.WriteLine("App is now in foreground"); }; lifecycle.OnEnterBackground += () => { // Pause timers, save state, or disconnect services Console.WriteLine("App moved to background"); }; lifecycle.Initialize();

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Comparison With Other Approaches

Approach	Pros	Cons
Manual platform hooks (AppDelegate, MainActivity)	Full control	Repetitive, platform-specific, verbose
MessagingCenter / EventAggregator	Decoupled	Boilerplate, hard to maintain cross-platform consistency
Shaunebu.MAUI.Lifecycle	Unified API, cross-platform, minimal setup	Limited to foreground/background events, no full lifecycle details

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Notes & Best Practices

• Always initialize the manager once, preferably in App.xaml.cs.

• Use the events to pause or resume services, timers, or network requests.

• On Windows, background detection is approximate; consider additional checks for multi-window apps.

• Events are safe to call UI code, but consider Dispatcher.Dispatch if you encounter threading issues.

• No extra configuration is required for Android/iOS/Windows, but for advanced use cases you may extend the library with custom platform hooks.

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Example: Integrating With Services

lifecycle.OnEnterForeground += () => { MySyncService.Instance.Resume(); }; lifecycle.OnEnterBackground += () => { MySyncService.Instance.Pause(); };

This allows service management across platforms seamlessly.

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Diagram

::: mermaid flowchart TD; App --> LifecycleManager LifecycleManager -->|Foreground| ForegroundEvent LifecycleManager -->|Background| BackgroundEvent ForegroundEvent --> Services BackgroundEvent --> Services :::

• App initializes the manager.

• LifecycleManager handles platform-specific hooks.

• Events notify services or UI logic of state changes.

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FAQ

Q: Do I need extra permissions?
A: No, all events are internal hooks to MAUI lifecycle.

Q: Can I manually trigger foreground/background?
A: Yes, via InvokeForeground() and InvokeBackground().

Q: Can it detect app termination?
A: No, termination is not detectable reliably across all platforms.