<!-- MyApp.csproj -->
<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFrameworks>net8.0-android;net8.0-ios;net8.0-maccatalyst</TargetFrameworks>
    <TargetFrameworks Condition="$([MSBuild]::IsOSPlatform('windows'))">
      $(TargetFrameworks);net8.0-windows10.0.19041.0
    </TargetFrameworks>
    <OutputType>Exe</OutputType>
    <UseMaui>true</UseMaui>
    <SingleProject>true</SingleProject>
    <RootNamespace>MyApp</RootNamespace>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="CommunityToolkit.Mvvm" Version="8.*" />
    <PackageReference Include="CommunityToolkit.Maui" Version="9.*" />
  </ItemGroup>
</Project>

MyApp/
  MyApp/
    App.xaml / App.xaml.cs            # Application entry, resource dictionaries
    AppShell.xaml / AppShell.xaml.cs  # Shell navigation definition
    MauiProgram.cs                   # Host builder, DI, service registration
    MainPage.xaml / MainPage.xaml.cs  # Initial page
    ViewModels/                      # MVVM ViewModels
    Views/                           # XAML pages
    Models/                          # Data models
    Services/                        # Service interfaces and implementations
    Resources/
      Fonts/                         # Custom fonts (.ttf/.otf)
      Images/                        # SVG/PNG images (auto-resized per platform)
      Styles/                        # Shared styles, colors, resource dictionaries
      Raw/                           # Raw assets (JSON, etc.)
      Splash/                        # Splash screen image
    Platforms/
      Android/                       # AndroidManifest.xml, MainActivity.cs
      iOS/                           # Info.plist, AppDelegate.cs
      MacCatalyst/                   # Info.plist, AppDelegate.cs
      Windows/                       # Package.appxmanifest, App.xaml
    Properties/
      launchSettings.json
  MyApp.Tests/                       # Unit tests

<!-- Resources are configured in .csproj ItemGroups -->
<ItemGroup>
  <!-- SVG/PNG images: MAUI resizes for each platform density -->
  <MauiImage Include="Resources\Images\*" />

  <!-- Fonts: registered automatically -->
  <MauiFont Include="Resources\Fonts\*" />

  <!-- Splash screen -->
  <MauiSplashScreen Include="Resources\Splash\splash.svg"
                    Color="#512BD4" BaseSize="128,128" />

  <!-- App icon -->
  <MauiIcon Include="Resources\AppIcon\appicon.svg"
            ForegroundFile="Resources\AppIcon\appiconfg.svg"
            Color="#512BD4" />
</ItemGroup>

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:vm="clr-namespace:MyApp.ViewModels"
             x:Class="MyApp.Views.ProductListPage"
             x:DataType="vm:ProductListViewModel">

    <VerticalStackLayout Padding="16" Spacing="12">
        <SearchBar Text="{Binding SearchTerm}"
                   SearchCommand="{Binding SearchCommand}" />

        <CollectionView ItemsSource="{Binding Products}"
                        SelectionMode="Single"
                        SelectionChangedCommand="{Binding SelectProductCommand}"
                        SelectionChangedCommandParameter="{Binding SelectedItem,
                            Source={RelativeSource Self}}">
            <CollectionView.ItemTemplate>
                <DataTemplate x:DataType="model:Product">
                    <Frame Padding="12" Margin="0,4">
                        <HorizontalStackLayout Spacing="12">
                            <Image Source="{Binding ImageUrl}"
                                   HeightRequest="60" WidthRequest="60" />
                            <VerticalStackLayout>
                                <Label Text="{Binding Name}"
                                       FontAttributes="Bold" />
                                <Label Text="{Binding Price, StringFormat='{0:C}'}"
                                       TextColor="Gray" />
                            </VerticalStackLayout>
                        </HorizontalStackLayout>
                    </Frame>
                </DataTemplate>
            </CollectionView.ItemTemplate>
        </CollectionView>
    </VerticalStackLayout>
</ContentPage>

// ViewModels/ProductListViewModel.cs
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;

public partial class ProductListViewModel : ObservableObject
{
    private readonly IProductService _productService;
    private readonly INavigationService _navigationService;

    public ProductListViewModel(
        IProductService productService,
        INavigationService navigationService)
    {
        _productService = productService;
        _navigationService = navigationService;
    }

    [ObservableProperty]
    [NotifyCanExecuteChangedFor(nameof(SearchCommand))]
    private string _searchTerm = "";

    [ObservableProperty]
    private ObservableCollection<Product> _products = [];

    [ObservableProperty]
    private bool _isLoading;

    [RelayCommand]
    private async Task LoadProductsAsync(CancellationToken ct)
    {
        IsLoading = true;
        try
        {
            var items = await _productService.GetProductsAsync(ct);
            Products = new ObservableCollection<Product>(items);
        }
        finally
        {
            IsLoading = false;
        }
    }

    [RelayCommand(CanExecute = nameof(CanSearch))]
    private async Task SearchAsync(CancellationToken ct)
    {
        var results = await _productService.SearchAsync(SearchTerm, ct);
        Products = new ObservableCollection<Product>(results);
    }

    private bool CanSearch() => !string.IsNullOrWhiteSpace(SearchTerm);

    [RelayCommand]
    private async Task SelectProductAsync(Product? product)
    {
        if (product is null) return;
        await _navigationService.GoToAsync(
            nameof(ProductDetailPage),
            new Dictionary<string, object> { ["Product"] = product });
    }
}

<!-- AppShell.xaml -->
<Shell xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
       xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
       xmlns:views="clr-namespace:MyApp.Views"
       x:Class="MyApp.AppShell">

    <!-- Tab-based navigation -->
    <TabBar>
        <ShellContent Title="Products"
                      Icon="products.png"
                      ContentTemplate="{DataTemplate views:ProductListPage}" />

        <ShellContent Title="Cart"
                      Icon="cart.png"
                      ContentTemplate="{DataTemplate views:CartPage}" />

        <ShellContent Title="Profile"
                      Icon="profile.png"
                      ContentTemplate="{DataTemplate views:ProfilePage}" />
    </TabBar>
</Shell>

// Register routes for pages not in the Shell visual hierarchy
// (pushed onto the navigation stack, not direct Shell tabs)
public partial class AppShell : Shell
{
    public AppShell()
    {
        InitializeComponent();
        Routing.RegisterRoute(nameof(ProductDetailPage), typeof(ProductDetailPage));
        Routing.RegisterRoute(nameof(CheckoutPage), typeof(CheckoutPage));
    }
}

// Navigate with parameters
await Shell.Current.GoToAsync(nameof(ProductDetailPage),
    new Dictionary<string, object>
    {
        ["Product"] = selectedProduct
    });

// Receive parameters via QueryProperty
[QueryProperty(nameof(Product), "Product")]
public partial class ProductDetailViewModel : ObservableObject
{
    [ObservableProperty]
    private Product _product = null!;
}

public partial class ProductListPage : ContentPage
{
    private readonly ProductListViewModel _viewModel;

    public ProductListPage(ProductListViewModel viewModel)
    {
        InitializeComponent();
        _viewModel = viewModel;
        BindingContext = viewModel;
    }

    protected override async void OnAppearing()
    {
        base.OnAppearing();
        // Load data when page appears (not in constructor)
        await _viewModel.LoadProductsCommand.ExecuteAsync(null);
    }

    protected override void OnDisappearing()
    {
        base.OnDisappearing();
        // Cancel pending operations, unsubscribe events
    }
}

// Services/IDeviceService.cs (shared interface)
public interface IDeviceService
{
    string GetDeviceIdentifier();
    Task<bool> HasBiometricAsync();
}

// Services/DeviceService.cs (shared partial class)
public partial class DeviceService : IDeviceService
{
    public partial string GetDeviceIdentifier();
    public partial Task<bool> HasBiometricAsync();
}

// Platforms/Android/Services/DeviceService.cs
public partial class DeviceService
{
    public partial string GetDeviceIdentifier()
    {
        return Android.Provider.Settings.Secure.GetString(
            Android.App.Application.Context.ContentResolver,
            Android.Provider.Settings.Secure.AndroidId) ?? "unknown";
    }

    public partial Task<bool> HasBiometricAsync()
    {
        var manager = BiometricManager.From(Android.App.Application.Context);
        var result = manager.CanAuthenticate(
            BiometricManager.Authenticators.BiometricStrong);
        return Task.FromResult(
            result == BiometricManager.BiometricSuccess);
    }
}

// Platforms/iOS/Services/DeviceService.cs
public partial class DeviceService
{
    public partial string GetDeviceIdentifier()
    {
        return UIKit.UIDevice.CurrentDevice.IdentifierForVendor?.ToString()
            ?? "unknown";
    }

    public partial Task<bool> HasBiometricAsync()
    {
        var context = new LocalAuthentication.LAContext();
        return Task.FromResult(context.CanEvaluatePolicy(
            LocalAuthentication.LAPolicy.DeviceOwnerAuthenticationWithBiometrics,
            out _));
    }
}

public void ConfigurePlatformDefaults()
{
#if ANDROID
    // Android-specific: request permissions
    Platform.CurrentActivity?.RequestPermissions(
        [Android.Manifest.Permission.Camera]);
#elif IOS || MACCATALYST
    // iOS/Mac Catalyst: no runtime permission request needed for camera
    // (handled via Info.plist NSCameraUsageDescription)
#elif WINDOWS
    // Windows: WinUI-specific configuration
#endif
}

// MauiProgram.cs
public static class MauiProgram
{
    public static MauiApp CreateMauiApp()
    {
        var builder = MauiApp.CreateBuilder();
        builder
            .UseMauiApp<App>()
            .UseMauiCommunityToolkit()
            .ConfigureFonts(fonts =>
            {
                fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
                fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
            });

        // Services
        builder.Services.AddSingleton<IProductService, ProductService>();
        builder.Services.AddSingleton<INavigationService, NavigationService>();
        builder.Services.AddTransient<IDeviceService, DeviceService>();

        // HTTP client
        builder.Services.AddHttpClient("api", client =>
        {
            client.BaseAddress = new Uri("https://api.example.com");
        });

        // ViewModels (transient so each page gets a fresh instance)
        builder.Services.AddTransient<ProductListViewModel>();
        builder.Services.AddTransient<ProductDetailViewModel>();

        // Pages (transient, resolved with DI-injected ViewModels)
        builder.Services.AddTransient<ProductListPage>();
        builder.Services.AddTransient<ProductDetailPage>();

        // For DI patterns beyond MAUI-specific registration, see [skill:dotnet-csharp-dependency-injection]

#if DEBUG
        builder.Logging.AddDebug();
#endif

        return builder.Build();
    }
}

<!-- WinUI 3 project -->
<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0-windows10.0.19041.0</TargetFramework>
    <UseWinUI>true</UseWinUI>
  </PropertyGroup>
</Project>

<!-- .NET 11: XAML source gen is ON by default -->
<!-- To revert to legacy XAMLC (if source gen causes issues): -->
<PropertyGroup>
  <MauiXamlInflator>XamlC</MauiXamlInflator>
</PropertyGroup>

<!-- .NET 11: CoreCLR is the default for Android Release builds -->
<!-- To opt out and continue using Mono: -->
<PropertyGroup>
  <UseMonoRuntime>true</UseMonoRuntime>
</PropertyGroup>

# .NET 11: interactive device selection
dotnet run --project MyApp/MyApp.csproj
# Prompts: Select target framework:
#   1. net11.0-android
#   2. net11.0-ios
#   3. net11.0-maccatalyst
# Then: Select device:
#   1. Pixel 7 API 34 (emulator)
#   2. Samsung Galaxy S24 (physical)

# Skip interactive selection with explicit TFM
dotnet run --project MyApp/MyApp.csproj -f net11.0-android

# CLI: Hot Reload is enabled automatically in Debug configuration
dotnet run --project MyApp/MyApp.csproj -f net8.0-android

# Visual Studio: Hot Reload is on by default (fire icon in toolbar)
# VS Code: Use MAUI extension with Hot Reload enabled