No,Category,Guideline,Description,Do,Don't,Code Good,Code Bad,Severity,Docs URL
1,XAML,Use WinUI XAML API surface,Uno implements the WinUI API across platforms,Microsoft.UI.Xaml namespace for all UI code,WPF or Xamarin.Forms namespaces,"using Microsoft.UI.Xaml.Controls;","using System.Windows.Controls; or using Xamarin.Forms;",High,https://platform.uno/docs/articles/implemented-views.html
2,XAML,Check API implementation status,Not all WinUI APIs are implemented on every platform,Uno API compatibility docs before using new APIs,Assuming all WinUI APIs work everywhere,"Check platform.uno/docs for API status","Using unimplemented API and discovering at runtime",High,https://platform.uno/docs/articles/implemented-views.html
3,XAML,Use Uno.WinUI not Uno.UI for new projects,Uno.WinUI uses WinUI 3 APIs,Uno.WinUI NuGet packages for new projects,Uno.UI (UWP API surface) for new projects,"<Project Sdk=""Uno.Sdk""> (Uno.WinUI / WinUI 3 surface implicit)","<PackageReference Include=""Uno.UI""/> (legacy UWP API surface)",Medium,https://platform.uno/docs/articles/updating-to-winui3.html
4,XAML,Use XAML Hot Reload,Speed up development with live XAML editing,Hot Reload for iterating on layouts,Restarting app for every XAML change,"Click Hot Reload button in VS toolbar or save in VS Code/Rider to apply XAML changes","Full rebuild for margin tweak",Medium,https://platform.uno/docs/articles/features/working-with-xaml-hot-reload.html
5,Conditional,Use platform-specific XAML,Conditional namespaces for platform-specific UI,xmlns:android xmlns:ios xmlns:wasm for platform XAML,Shared XAML when platforms need different controls,"<TextBlock android:Text=""Android"" ios:Text=""iOS"" Text=""Default""/>","#if in code-behind to set text per platform",Medium,https://platform.uno/docs/articles/platform-specific-xaml.html
6,Conditional,Use partial classes for platform code,Separate platform implementations in partial files,Partial class files with platform-specific logic,#if directives in shared code for large blocks,"MainPage.iOS.cs MainPage.Android.cs partial class files","#if __IOS__ ... #elif __ANDROID__ ... 100-line blocks in shared file",Medium,https://platform.uno/docs/articles/platform-specific-csharp.html
7,Conditional,Use preprocessor symbols correctly,Target correct platforms with defines,__IOS__ __ANDROID__ __WASM__ __DESKTOP__ for platform checks,Inventing custom symbols or checking OS at runtime,"#if __ANDROID__ Android-specific code #endif","if (RuntimeInformation.IsOSPlatform(OSPlatform.Android)) for compile-time choice",Medium,https://platform.uno/docs/articles/platform-specific-csharp.html
8,Conditional,Minimize platform-specific code,Keep shared code maximized,Abstract platform differences behind interfaces,Duplicating logic across platform files,"IDeviceService with per-platform implementation","Same 50 lines copy-pasted into iOS and Android partial classes",High,https://platform.uno/docs/articles/platform-specific-csharp.html
9,Navigation,Use Frame-based navigation,Standard WinUI navigation pattern,Frame.Navigate with page types,Manual content swapping,"rootFrame.Navigate(typeof(DetailPage), parameter);","contentPresenter.Content = new DetailPage();",Medium,https://platform.uno/docs/articles/guides/native-frame-nav-tutorial.html
10,Navigation,Use Uno.Extensions.Navigation,Type-safe navigation with DI integration,Uno.Extensions navigation for complex apps,Manual Frame management in large apps,"navigator.NavigateViewModelAsync<DetailViewModel>(this, data: item);","Frame.Navigate with string parsing everywhere",Medium,https://platform.uno/docs/articles/external/uno.extensions/doc/Overview/Navigation/NavigationOverview.html
11,Navigation,Handle platform back navigation,SystemNavigationManager.BackRequested works on Android iOS and WASM but is unimplemented on WinAppSDK desktop where calling GetForCurrentView() throws at runtime,Subscribe to BackRequested only on platforms that support it or use Uno.Toolkit NavigationBar for cross-platform back UX,Calling SystemNavigationManager.GetForCurrentView() on WinUI 3 desktop without a guard,"#if __ANDROID__ || __IOS__ || __WASM__ SystemNavigationManager.GetForCurrentView().BackRequested += OnBackRequested; #endif","SystemNavigationManager.GetForCurrentView().BackRequested += OnBackRequested; with no platform guard — crashes on Windows desktop",High,https://platform.uno/docs/articles/guides/native-frame-nav-tutorial.html
12,Navigation,Use deep linking,Support URI activation across platforms,Handle protocol activation and URI routing,Single entry point ignoring activation,Route URIs to specific pages on activation,Ignoring OnLaunched activation args,Medium,https://platform.uno/docs/articles/features/protocol-activation.html
13,Renderers,Understand Skia vs native rendering,Uno offers both rendering approaches,Skia for pixel-perfect cross-platform consistency,Assuming native rendering on all platforms,"<TargetFrameworks>net10.0-desktop;net10.0-browserwasm</TargetFrameworks> uses unified Skia Desktop shell","Expecting platform-native controls on Skia targets",High,https://platform.uno/docs/articles/features/using-skia-desktop.html
14,Renderers,Use unified net10.0-desktop target,Uno 5.2+ ships a single Skia Desktop shell that auto-selects X11 Win32 or AppKit per OS — Skia.Gtk Skia.Linux.Framebuffer and Skia.WPF heads are deprecated,net10.0-desktop TFM with UnoPlatformHostBuilder for cross-platform desktop,Targeting the legacy Skia.Gtk or Skia.Linux.Framebuffer heads in new projects,"<TargetFrameworks>net10.0-desktop</TargetFrameworks> in the Uno.Sdk single project","Per-OS Skia.Gtk Skia.MacOS Skia.Linux.Framebuffer head projects",Medium,https://platform.uno/docs/articles/features/using-skia-desktop.html
15,Renderers,Test rendering on each target,Visual differences exist between renderers,Visual testing on each active target platform,Testing only on Windows assuming others match,"Screenshot tests on iOS Android WASM and Desktop","Testing only on Windows Desktop",High,https://platform.uno/docs/articles/external/uno.uitest/doc/using-uno-uitest.html
16,Renderers,Use platform-native features when needed,Access native APIs through Uno abstractions,Native platform APIs via platform-specific code,Avoiding native features for purity,"#if __IOS__ UIKit API call #endif for camera access","Pure shared code that avoids using the camera",Medium,https://platform.uno/docs/articles/platform-specific-csharp.html
17,Performance,Optimize WASM bundle size,WebAssembly downloads can be large,IL linker and AOT for smaller WASM bundles,Default settings for production WASM,"<WasmShellILLinkerEnabled>true</WasmShellILLinkerEnabled>","Publishing WASM without linker",High,https://platform.uno/docs/articles/features/using-il-linker-webassembly.html
18,Performance,Use x:Load for deferred XAML,Defer element creation until needed,x:Load=False for hidden panels and tabs,Loading all UI elements upfront,"<StackPanel x:Load=""{x:Bind ShowAdvanced}"">","Always-loaded Collapsed panels",Medium,https://platform.uno/docs/articles/features/windows-ui-xaml-xbind.html
19,Data Binding,Use x:Bind for compiled bindings,Compiled bindings eliminate runtime reflection — Uno supports x:Bind across iOS Android WASM Skia and Windows targets that compile XAML so prefer it over {Binding} for static well-typed bindings,x:Bind for property and event bindings; reserve {Binding} for runtime-typed DataContext scenarios,{Binding} everywhere when x:Bind would compile,"<TextBlock Text=""{x:Bind ViewModel.Title, Mode=OneWay}""/>","<TextBlock Text=""{Binding Title}""/> for a statically known property",High,https://platform.uno/docs/articles/features/windows-ui-xaml-xbind.html
20,Performance,Profile per platform,Performance characteristics vary by target,Platform-specific profiling tools,Assuming desktop perf equals mobile,"Instruments on iOS and Android Profiler on Android","Profiling only on Windows",Medium,https://platform.uno/docs/articles/guides/profiling-applications.html
21,Styling,Use WinUI theme resources,Consistent theming across platforms,ThemeResource for adaptive colors,Hardcoded colors per platform,"Background=""{ThemeResource ApplicationPageBackgroundThemeBrush}""","Background=""#FFFFFF""",High,https://platform.uno/docs/articles/features/working-with-themes.html
22,Styling,Support light and dark themes,Application.RequestedTheme accepts only ApplicationTheme.Light/Dark — to follow the system theme leave it unset entirely. ElementTheme.Default exists only on FrameworkElement.RequestedTheme not on Application,Omit Application.RequestedTheme so the OS theme wins; use RequestedTheme=Default on FrameworkElement to inherit from parent,Setting Application.RequestedTheme=""Default"" — not a valid ApplicationTheme value and throws at parse time,"<Application></Application> with RequestedTheme unset; <Grid RequestedTheme=""Default"">...</Grid> on a FrameworkElement","<Application RequestedTheme=""Default""> // not a valid ApplicationTheme",Medium,https://platform.uno/docs/articles/features/working-with-themes.html
23,Styling,Use Lightweight Styling,Override control sub-properties via resources,Lightweight styling keys for minor tweaks,Full ControlTemplate for small changes,"<Button><Button.Resources><StaticResource x:Key=""ButtonBackground"" ResourceKey=""AccentBrush""/></Button.Resources></Button>","Copying entire ControlTemplate to change one color",Medium,https://platform.uno/docs/articles/external/uno.themes/doc/lightweight-styling.html
24,Styling,Test themes on each platform,Theme rendering differs across platforms,Visual theme testing on all targets,Assuming themes look identical everywhere,"Screenshot comparison across platforms for themed controls","Theming only tested on Windows",Low,https://platform.uno/docs/articles/features/working-with-themes.html
25,Architecture,Use MVVM pattern,Separate view and logic,CommunityToolkit.Mvvm or Prism for MVVM,Code-behind for business logic,"[ObservableProperty] public partial string Title { get; set; } [RelayCommand] private void Save() { }","MainPage.xaml.cs with all logic",High,https://learn.microsoft.com/en-us/dotnet/communitytoolkit/mvvm/
26,Architecture,Use Uno.Extensions,Official extension libraries for common patterns,Uno.Extensions for DI navigation configuration,Building infrastructure from scratch,"Host.CreateDefaultBuilder().UseNavigation().UseConfiguration()","Manual DI and navigation setup",Medium,https://platform.uno/docs/articles/external/uno.extensions/doc/ExtensionsOverview.html
27,Architecture,Use dependency injection,Register services for testability,Microsoft.Extensions.DI through Uno.Extensions,Static service locators and singletons,"services.AddSingleton<IApiService, ApiService>();","ApiService.Instance or new ApiService() in ViewModels",Medium,https://platform.uno/docs/articles/external/uno.extensions/doc/Learn/DependencyInjection/DependencyInjectionOverview.html
28,Architecture,Share code via class libraries,Maximize code reuse across targets,Business logic in .NET Standard or shared library,Business logic in platform head projects,"MyApp.Core class library referenced by all heads","Business logic in MyApp.Wasm.csproj",Medium,https://platform.uno/docs/articles/cross-targeted-libraries.html
29,Architecture,Use Uno.Resizetizer for assets,Single source SVG to multi-platform assets,UnoImage for automatic asset generation from SVG,Manual asset export per resolution and platform,"<UnoImage Include=""Assets/icon.svg"" BaseSize=""24,24""/>","Manually exporting icon_1x.png icon_2x.png icon_3x.png per platform",Medium,https://platform.uno/docs/articles/external/uno.resizetizer/doc/using-uno-resizetizer.html
30,Accessibility,Set AutomationProperties,Enable screen readers across platforms,AutomationProperties.Name on interactive controls,Controls without accessible names,"<Button AutomationProperties.Name=""Submit form""><SymbolIcon Symbol=""Accept""/></Button>","<Button><SymbolIcon Symbol=""Accept""/></Button> without name",High,https://platform.uno/docs/articles/features/working-with-accessibility.html
31,Accessibility,Test accessibility per platform,Each platform has different assistive tech,Test with VoiceOver TalkBack and Narrator,Testing accessibility on one platform only,"VoiceOver on iOS + TalkBack on Android + Narrator on Windows","Only testing with Narrator on Windows",High,https://platform.uno/docs/articles/features/working-with-accessibility.html
32,Accessibility,Support platform text scaling,Respect user font size preferences,Dynamic font scaling for all text,Fixed font sizes ignoring accessibility,"FontSize=""{ThemeResource BodyTextBlockFontSize}""","FontSize=""14"" everywhere",Medium,https://platform.uno/docs/articles/features/working-with-accessibility.html
33,Testing,Unit test ViewModels,Test business logic independently,xUnit or MSTest on shared ViewModel code,UI testing only,"[Fact] public void LoadData_SetsItems() { vm.Load(); Assert.NotEmpty(vm.Items); }","Manual testing on each platform",Medium,https://platform.uno/docs/articles/external/uno.uitest/doc/using-uno-uitest.html
34,Testing,Use Uno.UITest for integration,Cross-platform UI testing framework,Uno.UITest for automated UI tests across platforms,Manual regression testing,"app.WaitForElement(""SaveButton""); app.Tap(""SaveButton"");","Manual click-through on each platform",Medium,https://platform.uno/docs/articles/external/uno.uitest/doc/using-uno-uitest.html
35,WASM,Show an extended splash screen on WASM,WASM bundle download and runtime startup take several seconds on first load — render branded UI immediately so users do not see a blank page (AOT and trimming are covered separately),Render a splash overlay in wwwroot/index.html that hides on first XAML navigation,Letting the user wait on a blank white page while the runtime boots,"index.html: <div id=""uno-loading"">Loading…</div> hidden via JS interop after first Frame.Navigate","No splash markup in index.html — 5-second blank page on first visit",Medium,https://platform.uno/docs/articles/external/uno.wasm.bootstrap/doc/runtime-execution-modes.html
36,WASM,Use AOT compilation for performance,Ahead-of-time compilation improves runtime speed,AOT for production WASM builds,Interpreter mode in production,"<WasmShellMonoRuntimeExecutionMode>InterpreterAndAOT</WasmShellMonoRuntimeExecutionMode>","Default interpreter mode in production deployment",Medium,https://platform.uno/docs/articles/external/uno.wasm.bootstrap/doc/runtime-execution-modes.html
37,WASM,Handle browser limitations,WASM runs in browser sandbox,Feature detection for browser APIs,Assuming desktop capabilities in browser,"[JSImport(""globalThis.hasApi"")] static partial bool HasApi(); #if __WASM__ if (HasApi()) { ... } #endif","#if __WASM__ StorageFile.GetFileFromPathAsync(""C:/data"") #endif",Medium,https://platform.uno/docs/articles/platform-specific-csharp.html
38,Controls,Use NavigationView for app shell,WinUI NavigationView for consistent navigation across platforms,NavigationView with MenuItems for app navigation,Custom hamburger menu implementation,"<NavigationView><NavigationView.MenuItems><NavigationViewItem Content=""Home"" Icon=""Home""/></NavigationView.MenuItems></NavigationView>","Custom SplitView with manual toggle button",High,https://learn.microsoft.com/en-us/windows/apps/develop/ui/controls/navigationview
39,Controls,Use ContentDialog for modal interactions,Cross-platform modal dialogs using WinUI API,ContentDialog for confirmations and input,Custom overlay Panel as dialog,"<ContentDialog Title=""Confirm"" PrimaryButtonText=""OK"" CloseButtonText=""Cancel""/>","Grid overlay with manual focus trapping",Medium,https://learn.microsoft.com/en-us/windows/apps/develop/ui/controls/dialogs-and-flyouts/dialogs
40,Controls,Use CommandBar for app actions,Standard command bar with primary and secondary commands,CommandBar with AppBarButtons for toolbar actions,Custom StackPanel toolbar,"<CommandBar><AppBarButton Icon=""Save"" Label=""Save""/><AppBarButton Icon=""Delete"" Label=""Delete""/></CommandBar>","<StackPanel Orientation=""Horizontal""><Button>Save</Button></StackPanel>",Medium,https://learn.microsoft.com/en-us/windows/apps/develop/ui/controls/command-bar
41,Controls,Use ToggleSwitch for boolean settings,Platform-native toggle control for on/off preferences,ToggleSwitch for settings and feature flags,CheckBox for toggle settings,"<ToggleSwitch Header=""Dark Mode"" IsOn=""{x:Bind ViewModel.IsDarkMode, Mode=TwoWay}""/>","<CheckBox Content=""Enable dark mode""/>",Low,https://learn.microsoft.com/en-us/windows/apps/develop/ui/controls/toggles
42,Data Binding,Implement INotifyPropertyChanged,Enable UI updates when ViewModel properties change,CommunityToolkit.Mvvm [ObservableProperty] for auto-notification,Properties without change notification,"[ObservableProperty] public partial string Title { get; set; }","public string Title { get; set; } without notification",High,https://learn.microsoft.com/en-us/dotnet/communitytoolkit/mvvm/
43,Data Binding,Use ObservableCollection for bound lists,Collection change notifications for ItemsSources across platforms,ObservableCollection<T> for data-bound lists,List<T> for bound ItemsSources,"ObservableCollection<Item> Items { get; } = new();","List<Item> Items { get; set; } = new();",High,https://learn.microsoft.com/en-us/dotnet/communitytoolkit/mvvm/
44,Lifecycle,Handle app suspension on mobile,iOS and Android may suspend or terminate the app — WinAppSDK desktop does not raise Suspending so use window Closed for desktop save-state,Save state in OnSuspending and restore on activation,Ignoring lifecycle losing user state on mobile,"Application.Current.Suspending += (s, e) => { var d = e.SuspendingOperation.GetDeferral(); SaveState(); d.Complete(); };","No suspend handler losing form data on mobile",High,https://platform.uno/docs/articles/features/windows-ui-xaml-application.html
45,Lifecycle,Use Uno.Extensions.Hosting for startup,Structured app initialization with DI and configuration,IHost builder pattern for app startup and service registration,Manual initialization in App constructor,"Host.CreateDefaultBuilder().ConfigureServices(s => s.AddSingleton<MainViewModel>()).Build();","new MainViewModel() in App.xaml.cs constructor",Medium,https://platform.uno/docs/articles/external/uno.extensions/doc/Overview/Hosting/HostingOverview.html
46,Performance,Use ListView virtualization for large lists,Only renders visible items to reduce memory and layout cost,ListView with default ItemsStackPanel virtualization,ItemsControl or StackPanel for large data sets,"<ListView ItemsSource=""{x:Bind Items}""/> (virtualizes by default)","<ItemsControl><StackPanel> rendering 5000 items at once",High,https://learn.microsoft.com/en-us/windows/apps/develop/ui/controls/listview-and-gridview
47,Accessibility,Support keyboard navigation on desktop,Skia and WinAppSDK targets need full keyboard operability — note TabIndex routing is not fully implemented on every Uno target,AccessKey and KeyboardAccelerator on Skia and WinAppSDK targets,Mouse-only interactions on desktop,"<Button AccessKey=""S"" Content=""Save""><Button.KeyboardAccelerators><KeyboardAccelerator Modifiers=""Control"" Key=""S""/></Button.KeyboardAccelerators></Button>","Clickable controls without keyboard support on desktop",High,https://learn.microsoft.com/en-us/windows/apps/develop/input/keyboard-accelerators
48,WASM,Use service workers for offline support,Enable PWA capabilities for WASM deployments,Service worker registration for caching and offline mode,Online-only WASM app with no offline fallback,"<WasmPWAManifestFile>manifest.webmanifest</WasmPWAManifestFile>","No service worker leaving WASM app unusable offline",Low,https://platform.uno/docs/articles/external/uno.wasm.bootstrap/doc/features-pwa.html
49,Performance,Marshal to UI thread with DispatcherQueue,Cross-thread access to UI elements throws — capture the UI DispatcherQueue once and use TryEnqueue to update from background work,DispatcherQueue.GetForCurrentThread().TryEnqueue from background work,Touching UI controls directly from a Task,"_dispatcher.TryEnqueue(() => StatusText.Text = ""Done"");","await Task.Run(() => StatusText.Text = ""Done""); throws on non-UI thread",High,https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/microsoft.ui.dispatching.dispatcherqueue
50,Styling,Merge XamlControlsResources in App.xaml,Required for Fluent control styles to load — without it controls render with no template,Add XamlControlsResources at the top of Application.Resources MergedDictionaries,Skipping the merged dictionary and wondering why Buttons look unstyled,"<Application.Resources><ResourceDictionary><ResourceDictionary.MergedDictionaries><XamlControlsResources xmlns=""using:Microsoft.UI.Xaml.Controls""/></ResourceDictionary.MergedDictionaries></ResourceDictionary></Application.Resources>","<Application.Resources><SolidColorBrush x:Key=""MyBrush"" Color=""Red""/></Application.Resources> with no XamlControlsResources merged",High,https://platform.uno/docs/articles/features/fluent-styles.html
51,Architecture,Use async [RelayCommand] for I/O,AsyncRelayCommand reports CanExecute=false (raising CanExecuteChanged) and exposes IsRunning while the Task is in flight — the bound control is disabled and re-entrancy is prevented by default (AllowConcurrentExecutions=false),[RelayCommand] on a Task-returning method for awaitable work,async void event handlers calling .Wait() or .Result,"[RelayCommand] private async Task LoadAsync() { Items = await _api.GetAsync(); }","public void OnLoadClick(object s, EventArgs e) { LoadAsync().Wait(); } deadlock risk",Medium,https://learn.microsoft.com/en-us/dotnet/communitytoolkit/mvvm/generators/relaycommand
52,Architecture,Use x:Uid for localized strings,WinUI x:Uid resolves UI text from .resw resources at runtime — use it instead of hardcoded strings to support localization across iOS Android WASM and desktop from a single project,x:Uid on every user-facing string with matching .resw entries per language under Strings/{lang}/Resources.resw,Hardcoding language-specific strings into XAML or code-behind,"<Button x:Uid=""SubmitButton""/> with Strings/en/Resources.resw entry SubmitButton.Content=Submit","<Button Content=""Submit""/> hardcoded in XAML",High,https://platform.uno/docs/articles/features/working-with-strings.html
53,Architecture,Wire up ILogger via Uno.Extensions.Logging,Cross-platform logging routes to platform-native sinks (OSLog on iOS Console on WASM Debug elsewhere) when configured through the IHost builder,Inject ILogger<T> into ViewModels and services and call UseLogging() on the host builder,Console.WriteLine or platform-specific log APIs scattered across shared code,"Host.CreateDefaultBuilder().UseLogging(c => c.SetMinimumLevel(LogLevel.Information)) and ILogger<MainViewModel> via constructor injection","Console.WriteLine(""error"") in shared code with no platform-aware routing",Medium,https://platform.uno/docs/articles/external/uno.extensions/doc/Overview/Logging/LoggingOverview.html
54,Performance,Enable PublishAot on net10.0-desktop,Skia Desktop on .NET 10 supports Native AOT for faster cold start and smaller deployments — opt in per-target so debug builds remain fast,<PublishAot>true</PublishAot> in a TFM-conditional PropertyGroup for net10.0-desktop release builds,Enabling PublishAot globally and breaking debug iteration on every TFM,"<PropertyGroup Condition=""'$(TargetFramework)'=='net10.0-desktop' AND '$(Configuration)'=='Release'""><PublishAot>true</PublishAot></PropertyGroup>","<PublishAot>true</PublishAot> at root with no TFM/Configuration condition",Medium,https://platform.uno/docs/articles/features/using-skia-desktop.html
55,Performance,Never block on async with .Result or .Wait(),Blocking on a Task from the UI thread deadlocks because the awaiter cannot resume on the captured SynchronizationContext — always await async APIs through to the event handler,Await async methods all the way up; in libraries call ConfigureAwait(false) to avoid context capture,Calling .Result .Wait() or GetAwaiter().GetResult() on a Task from the UI thread,"private async void OnLoadClick(object s, RoutedEventArgs e) { var data = await _api.GetAsync(); Items = data; }","private void OnLoadClick(object s, RoutedEventArgs e) { var data = _api.GetAsync().Result; } // deadlocks on UI thread",High,https://learn.microsoft.com/en-us/dotnet/csharp/asynchronous-programming/
56,Styling,Define ThemeDictionaries for Light Dark and HighContrast,Resources placed inside ResourceDictionary.ThemeDictionaries entries are automatically swapped when the system theme changes — required for theme-aware brushes,Wrap brushes in a ThemeDictionaries dictionary keyed by Light Dark and HighContrast in App.xaml or page resources,Defining a single brush at the root and missing dark/high-contrast variants,"<ResourceDictionary.ThemeDictionaries><ResourceDictionary x:Key=""Light""><SolidColorBrush x:Key=""Brand"" Color=""#005A9E""/></ResourceDictionary><ResourceDictionary x:Key=""Dark""><SolidColorBrush x:Key=""Brand"" Color=""#3A96DD""/></ResourceDictionary></ResourceDictionary.ThemeDictionaries>","<SolidColorBrush x:Key=""Brand"" Color=""#005A9E""/> at root with no theme variants",Medium,https://platform.uno/docs/articles/features/working-with-themes.html
57,Architecture,Use Uno.Sdk with UnoFeatures,Uno.Sdk is the modern single-project SDK that auto-resolves Uno.WinUI Uno.Toolkit Material and other packages from a UnoFeatures property — declare features by name instead of hand-managing dozens of PackageReferences,Declare features in the csproj via <UnoFeatures>...</UnoFeatures> and let the SDK resolve transitive packages,Hand-adding every Uno.* PackageReference and matching version numbers across packages,"<Project Sdk=""Uno.Sdk""><PropertyGroup><UnoFeatures>Material;Hosting;Toolkit;Logging;MVVM</UnoFeatures></PropertyGroup></Project>","<PackageReference Include=""Uno.WinUI""/><PackageReference Include=""Uno.Material.WinUI""/> ... duplicated per feature with mismatched versions",Medium,https://platform.uno/docs/articles/features/using-the-uno-sdk.html
58,Lifecycle,Persist desktop window state via Window.Closed,WinAppSDK and Skia desktop heads do not raise Application.Suspending — handle the Window.Closed event (and AppWindow size/position changes) to save user state when desktop apps shut down,Subscribe to MainWindow.Closed and persist any unsaved state before the window is destroyed,Relying on Application.Suspending to fire on desktop targets,"m_window.Closed += (s, e) => SaveState();","Application.Current.Suspending += SaveState; // never fires on WinAppSDK or Skia desktop",Medium,https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.window
59,Architecture,Use WinRT.Interop for native window handle on Windows,Calling Win32 APIs from a WinUI Window (file pickers icon embedding etc.) requires the HWND — retrieve it via WinRT.Interop.WindowNative.GetWindowHandle and guard the call so non-Windows targets stay unaffected,GetWindowHandle inside a #if WINDOWS block when you need the HWND,Calling WinRT.Interop in shared code without a platform guard,"#if WINDOWS\nvar hWnd = WinRT.Interop.WindowNative.GetWindowHandle(MainWindow);\n#endif","var hWnd = WinRT.Interop.WindowNative.GetWindowHandle(MainWindow); // breaks build on iOS Android WASM",Medium,https://learn.microsoft.com/en-us/windows/apps/develop/ui/retrieve-hwnd