Persistent Services

The most powerful feature of Stores. Register an INotifyPropertyChanged class as a persistent service, and every property change is automatically written to the backing store. When the app restarts, the object is rehydrated from the store.

Create a class that implements INotifyPropertyChanged:

[Reflector] // Optional but recommended — removes reflection for AOT safety
public partial class AppSettings : INotifyPropertyChanged
{
    string theme = "light";
    public string Theme
    {
        get => theme;
        set { theme = value; OnPropertyChanged(); }
    }

    bool notificationsEnabled = true;
    public bool NotificationsEnabled
    {
        get => notificationsEnabled;
        set { notificationsEnabled = value; OnPropertyChanged(); }
    }

    // INotifyPropertyChanged implementation
    public event PropertyChangedEventHandler? PropertyChanged;
    void OnPropertyChanged([CallerMemberName] string? name = null)
        => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
}

// Uses the default "settings" store
builder.Services.AddPersistentService<AppSettings>();

// Or target a specific store
builder.Services.AddPersistentService<SecureSettings>("secure");

Inject and use — changes are persisted automatically:

public class SettingsViewModel(AppSettings settings)
{
    public AppSettings Settings => settings;

    public void ToggleNotifications()
    {
        // This change is automatically persisted to the store
        Settings.NotificationsEnabled = !Settings.NotificationsEnabled;
    }
}