Overview
.NET MAUI raises cross-platform lifecycle events on the Window class when the app transitions states.
State Transitions
| Begin State | Event | End State |
|---|---|---|
| Running | Deactivated | Deactivated |
| Deactivated | Stopped | Stopped |
| Stopped | Resumed | Running |
| Stopped | Destorying | Not running |
| Not running | Created, Activated | Running |
Events
Note: These events have different names on Android, iOS.
| Event | Raised when | Action |
|---|---|---|
| Created | Native window created (but perhaps not yet visible) | N/A |
| Activated | Window activated | N/A |
| Deactivated | Window no longer focused | N/A |
| Stopped | Window no longer visible | Disconnect; cancel pending requests |
| Resumed | App resumes from being Stopped (never raised first time app launches) | Subscribe to events; refresh content that’s visible on the page |
| Destroying | Native window is being destroyed | Remove event subscriptions attached to the native window. |
Window Class Virtual Methods
These methods are invoked when the corresponding event is raised:
OnCreated, OnActivated, OnDeactivated, OnStopped, OnResumed, OnDestroying
Subscribing to Window Lifecycle Events
Override the CreateWindow method in App class and create a Window instance:
public partial class App : Application
{
public App()
{
InitializeComponent();
MainPage = new MainPage();
}
protected override Window CreateWindow(IActivationState activationState)
{
Window window = base.CreateWindow(activationState);
window.Created += (s, e) =>
{
// Custom logic
};
return window;
}
}
Consuming Window Lifecycle Events
Create a class that derives from Window:
public class MyWindow : Window
{
public MyWindow() : base() { }
public MyWindow(Page page) : base(page)
{
// Note: if this constructor is used and `App.MainPage` is already set, `InvalidOperationException`
is thrown.
}
protected override void OnCreated()
{
// Register services
}
}
Then, override the CreateWindow method in App class and return a MyWindow instance.
Custom Lifecycle Events
