maui-app-lifecycle

Name: maui-app-lifecycle
Author: managedcode

461stars35forks

How to install maui-app-lifecycle?

managedcode/dotnet-skills/maui-app-lifecycle

$npx -y skills add managedcode/dotnet-skills --skill maui-app-lifecycle

Installs into the current project.

Summary

.NET MAUI app lifecycle guidance — the four app states, cross-platform Window lifecycle events (Created, Activated, Deactivated, Stopped, Resumed, Destroying), platform-specific lifecycle mapping, backgrounding and resume behavior, and state-preservation patterns. USE FOR: "app l

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SKILL.md

1	# .NET MAUI App Lifecycle
2
3	Handle application state transitions correctly in .NET MAUI. This skill covers the cross-platform Window lifecycle events, their platform-native mappings, and patterns for preserving state across backgrounding and resume cycles.
4
5	## When to Use
6
7	- Saving or restoring state when the app backgrounds or resumes
8	- Subscribing to Window lifecycle events (Created, Activated, Deactivated, Stopped, Resumed, Destroying)
9	- Hooking into platform-native lifecycle callbacks via `ConfigureLifecycleEvents`
10	- Deciding where to place initialization, teardown, or refresh logic
11	- Understanding the difference between Deactivated and Stopped
12
13	## When Not to Use
14
15	- Page-level navigation events — use Shell navigation guidance instead
16	- Registering services at startup — use dependency injection guidance instead
17	- Calling platform-specific APIs outside lifecycle context — use platform invoke guidance instead
18
19	## Inputs
20
21	- The target lifecycle transition (e.g., "save draft when backgrounded", "refresh data on resume")
22	- Which platforms the developer targets (Android, iOS, Mac Catalyst, Windows)
23	- Whether the app uses multiple windows (iPad, Mac Catalyst, desktop Windows)
24
25	## App States
26
27	A .NET MAUI app moves through four states:
28
29	\| State \| Description \|
30	\|---\|---\|
31	\| Not Running \| Process does not exist \|
32	\| Running \| Foreground, receiving input \|
33	\| Deactivated \| Visible but lost focus (dialog, split-screen, notification shade) \|
34	\| Stopped \| Fully backgrounded, UI not visible \|
35
36	Typical flow: Not Running → Running → Deactivated → Stopped → Running (resumed) or Not Running (terminated).
37
38	## Window Lifecycle Events
39
40	`Microsoft.Maui.Controls.Window` exposes six cross-platform events:
41
42	\| Event \| Fires when \|
43	\|---\|---\|
44	\| `Created` \| Native window allocated \|
45	\| `Activated` \| Window receives input focus \|
46	\| `Deactivated` \| Window loses focus (may still be visible) \|
47	\| `Stopped` \| Window is no longer visible \|
48	\| `Resumed` \| Window returns to foreground after Stopped \|
49	\| `Destroying` \| Native window is being torn down \|
50
51	### Subscribing via CreateWindow
52
53	Override `CreateWindow` in your `App` class and attach event handlers:
54
55	```csharp
56	public partial class App : Application
57	{
58	protected override Window CreateWindow(IActivationState? activationState)
59	{
60	var window = base.CreateWindow(activationState);
61
62	window.Created += (s, e) => Debug.WriteLine("Created");
63	window.Activated += (s, e) => Debug.WriteLine("Activated");
64	window.Deactivated += (s, e) => Debug.WriteLine("Deactivated");
65	window.Stopped += (s, e) => Debug.WriteLine("Stopped");
66	window.Resumed += (s, e) => Debug.WriteLine("Resumed");
67	window.Destroying += (s, e) => Debug.WriteLine("Destroying");
68
69	return window;
70	}
71	}
72	```
73
74	### Subscribing via a Custom Window Subclass
75
76	Create a `Window` subclass and override the virtual methods:
77
78	```csharp
79	public class AppWindow : Window
80	{
81	public AppWindow(Page page) : base(page) { }
82
83	protected override void OnActivated() { /* refresh UI */ }
84	protected override void OnStopped() { /* save state */ }
85	protected override void OnResumed() { /* restore state */ }
86	protected override void OnDestroying() { /* cleanup */ }
87	}
88	```
89
90	Return it from `CreateWindow`:
91
92	```csharp
93	protected override Window CreateWindow(IActivationState? activationState)
94	=> new AppWindow(new AppShell());
95	```
96
97	## Workflow: Save and Restore State on Background
98
99	1. Identify transient state — draft text, scroll position, form inputs, timer values.
100	2. Save in `OnStopped` — use `Preferences` for small values or file serialization for larger state.
101	3. Restore in `OnResumed` — read back saved values and apply to your view model.
102	4. Also save in `OnDestroying` on Android — the back button can skip `Stopped` entirely.
103	5. Keep handlers fast — complete within 1–2 seconds to avoid ANR on Android or watchdog kills on iOS.
104
105	```csharp
106	protected override void OnStopped()
107	{
108	base.OnStopped();
109	Preferences.Set("draft_text", _viewModel.DraftText);
110	Preferences.Set("scroll_y", _viewModel.ScrollY);
111	}
112
113	protected override void OnResumed()
114	{
115	base.OnResumed();
116	_viewModel.DraftText = Preferences.Get("draft

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maui-app-lifecycle

461stars35forks

View on GitHub

How to install maui-app-lifecycle?

managedcode/dotnet-skills/maui-app-lifecycle

$npx -y skills add managedcode/dotnet-skills --skill maui-app-lifecycle

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# .NET MAUI App Lifecycle
2
3	Handle application state transitions correctly in .NET MAUI. This skill covers the cross-platform Window lifecycle events, their platform-native mappings, and patterns for preserving state across backgrounding and resume cycles.
4
5	## When to Use
6
7	- Saving or restoring state when the app backgrounds or resumes
8	- Subscribing to Window lifecycle events (Created, Activated, Deactivated, Stopped, Resumed, Destroying)
9	- Hooking into platform-native lifecycle callbacks via `ConfigureLifecycleEvents`
10	- Deciding where to place initialization, teardown, or refresh logic
11	- Understanding the difference between Deactivated and Stopped
12
13	## When Not to Use
14
15	- Page-level navigation events — use Shell navigation guidance instead
16	- Registering services at startup — use dependency injection guidance instead
17	- Calling platform-specific APIs outside lifecycle context — use platform invoke guidance instead
18
19	## Inputs
20
21	- The target lifecycle transition (e.g., "save draft when backgrounded", "refresh data on resume")
22	- Which platforms the developer targets (Android, iOS, Mac Catalyst, Windows)
23	- Whether the app uses multiple windows (iPad, Mac Catalyst, desktop Windows)
24
25	## App States
26
27	A .NET MAUI app moves through four states:
28
29	\| State \| Description \|
30	\|---\|---\|
31	\| Not Running \| Process does not exist \|
32	\| Running \| Foreground, receiving input \|
33	\| Deactivated \| Visible but lost focus (dialog, split-screen, notification shade) \|
34	\| Stopped \| Fully backgrounded, UI not visible \|
35
36	Typical flow: Not Running → Running → Deactivated → Stopped → Running (resumed) or Not Running (terminated).
37
38	## Window Lifecycle Events
39
40	`Microsoft.Maui.Controls.Window` exposes six cross-platform events:
41
42	\| Event \| Fires when \|
43	\|---\|---\|
44	\| `Created` \| Native window allocated \|
45	\| `Activated` \| Window receives input focus \|
46	\| `Deactivated` \| Window loses focus (may still be visible) \|
47	\| `Stopped` \| Window is no longer visible \|
48	\| `Resumed` \| Window returns to foreground after Stopped \|
49	\| `Destroying` \| Native window is being torn down \|
50
51	### Subscribing via CreateWindow
52
53	Override `CreateWindow` in your `App` class and attach event handlers:
54
55	```csharp
56	public partial class App : Application
57	{
58	protected override Window CreateWindow(IActivationState? activationState)
59	{
60	var window = base.CreateWindow(activationState);
61
62	window.Created += (s, e) => Debug.WriteLine("Created");
63	window.Activated += (s, e) => Debug.WriteLine("Activated");
64	window.Deactivated += (s, e) => Debug.WriteLine("Deactivated");
65	window.Stopped += (s, e) => Debug.WriteLine("Stopped");
66	window.Resumed += (s, e) => Debug.WriteLine("Resumed");
67	window.Destroying += (s, e) => Debug.WriteLine("Destroying");
68
69	return window;
70	}
71	}
72	```
73
74	### Subscribing via a Custom Window Subclass
75
76	Create a `Window` subclass and override the virtual methods:
77
78	```csharp
79	public class AppWindow : Window
80	{
81	public AppWindow(Page page) : base(page) { }
82
83	protected override void OnActivated() { /* refresh UI */ }
84	protected override void OnStopped() { /* save state */ }
85	protected override void OnResumed() { /* restore state */ }
86	protected override void OnDestroying() { /* cleanup */ }
87	}
88	```
89
90	Return it from `CreateWindow`:
91
92	```csharp
93	protected override Window CreateWindow(IActivationState? activationState)
94	=> new AppWindow(new AppShell());
95	```
96
97	## Workflow: Save and Restore State on Background
98
99	1. Identify transient state — draft text, scroll position, form inputs, timer values.
100	2. Save in `OnStopped` — use `Preferences` for small values or file serialization for larger state.
101	3. Restore in `OnResumed` — read back saved values and apply to your view model.
102	4. Also save in `OnDestroying` on Android — the back button can skip `Stopped` entirely.
103	5. Keep handlers fast — complete within 1–2 seconds to avoid ANR on Android or watchdog kills on iOS.
104
105	```csharp
106	protected override void OnStopped()
107	{
108	base.OnStopped();
109	Preferences.Set("draft_text", _viewModel.DraftText);
110	Preferences.Set("scroll_y", _viewModel.ScrollY);
111	}
112
113	protected override void OnResumed()
114	{
115	base.OnResumed();
116	_viewModel.DraftText = Preferences.Get("draft

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