Module Interfaces

WPF UI v4.2.0 | Public and internal API surface per module

This document defines the public vs internal API surface for each module in the WPF UI solution. It serves as the contract specification for inter-module communication and consumer-facing APIs.

Module Dependency Graph

mermaid

graph TD
    subgraph "Public API Surface"
        Abstractions["<b>Wpf.Ui.Abstractions</b>
<i>Public: 6 types</i>
<i>Internal: none</i>"]
        Core["<b>Wpf.Ui</b>
<i>Public: 77+ controls, 6 services,
managers, converters, markup</i>
<i>Internal: Win32, Interop</i>"]
        DI["<b>Wpf.Ui.DependencyInjection</b>
<i>Public: 2 types</i>
<i>Internal: none</i>"]
        Tray["<b>Wpf.Ui.Tray</b>
<i>Public: 4 types</i>
<i>Internal: 7 types</i>"]
        Syntax["<b>Wpf.Ui.SyntaxHighlight</b>
<i>Public: 2 types</i>
<i>Internal: 2 types</i>"]
    end

    subgraph "Non-Distributable"
        Toast["<b>Wpf.Ui.ToastNotifications</b>
<i>Public: 1 type (STUB)</i>"]
        FlaUI["<b>Wpf.Ui.FlaUI</b>
<i>Public: 1 type</i>"]
        FontMapper["<b>Wpf.Ui.FontMapper</b>
<i>Build-time tool</i>"]
    end

    Core --> Abstractions
    DI --> Abstractions
    Tray --> Core
    Syntax --> Core

    style Abstractions fill:#e1f5ff,stroke:#0277bd
    style Core fill:#fff4e1,stroke:#f57f17
    style DI fill:#e8f5e9,stroke:#2e7d32
    style Tray fill:#e8f5e9,stroke:#2e7d32
    style Syntax fill:#e8f5e9,stroke:#2e7d32
    style Toast fill:#fff9c4,stroke:#f9a825
    style FlaUI fill:#f3e5f5,stroke:#6a1b9a
    style FontMapper fill:#f3e5f5,stroke:#6a1b9a

Module: Wpf.Ui.Abstractions

NuGet: WPF-UI.Abstractions TFMs: net10.0, net9.0, net8.0, net462, netstandard2.1, netstandard2.0 Dependencies: None (zero external dependencies)

Public Types

Type	Kind	Description
`INavigationViewPageProvider`	Interface	Resolves page instances by type for NavigationView
`INavigableView<T>`	Interface	Associates a view with its ViewModel type
`INavigationAware`	Interface	Lifecycle callbacks for navigation (OnNavigatedTo/From)
`NavigationAware`	Abstract class	Base implementation of `INavigationAware`
`NavigationException`	Exception	Thrown when navigation operations fail
`NavigationViewPageProviderExtensions`	Static class	Extension methods for `INavigationViewPageProvider`

Internal Types

None. This module is entirely public by design -- it defines the contract surface.

Module: Wpf.Ui (Core)

NuGet: WPF-UI TFMs: net10.0-windows, net9.0-windows, net8.0-windows, net481, net472, net462 Dependencies: Wpf.Ui.Abstractions, Microsoft.Windows.CsWin32 (build-time), System.Memory

Public Namespaces

Namespace	Contents
`Wpf.Ui`	`UiApplication`, service interfaces and implementations
`Wpf.Ui.Controls`	77+ Fluent Design controls
`Wpf.Ui.Appearance`	`ApplicationThemeManager`, `ApplicationAccentColorManager`, `SystemThemeWatcher`, `WindowBackgroundManager`
`Wpf.Ui.Converters`	18 `IValueConverter` implementations
`Wpf.Ui.Markup`	`ControlsDictionary`, `ThemesDictionary`, `SymbolIconExtension`, `FontIconExtension`, `ImageIconExtension`
`Wpf.Ui.Extensions`	14 extension method classes
`Wpf.Ui.Input`	`IRelayCommand`, `IRelayCommand<T>`, `RelayCommand<T>`

Public Service Interfaces

Interface	Implementation	Wraps
`INavigationService`	`NavigationService`	`INavigationView` control
`IContentDialogService`	`ContentDialogService`	`ContentDialog` control
`ISnackbarService`	`SnackbarService`	`Snackbar` control
`IThemeService`	`ThemeService`	`ApplicationThemeManager` (static)
`ITaskBarService`	`TaskBarService`	COM `ITaskbarList4`
`INavigationWindow`	—	Interface for windows hosting NavigationView

Internal / Should-Be-Internal Namespaces

Namespace	Status	Notes
`Wpf.Ui.Interop`	Currently public	Managed Win32 wrappers (`UnsafeNativeMethods`, `PInvoke`). Recommended for internalization (see RECOMMENDATIONS.md)
`Wpf.Ui.Win32`	Currently public	OS version utilities. Recommended for internalization

Note: Wpf.Ui.Interop and Wpf.Ui.Win32 expose raw P/Invoke declarations that are implementation details. Consumers should not depend on these namespaces. A future major version should mark them internal.

Module: Wpf.Ui.DependencyInjection

NuGet: WPF-UI.DependencyInjection TFMs: net10.0, net9.0, net8.0, net462, netstandard2.1, netstandard2.0 Dependencies: Wpf.Ui.Abstractions, Microsoft.Extensions.DependencyInjection.Abstractions 3.1.0

Public Types

Type	Kind	Description
`ServiceCollectionExtensions`	Static class	`AddNavigationViewPageProvider<T>()` extension method for `IServiceCollection`
`DependencyInjectionNavigationViewPageProvider`	Class	`INavigationViewPageProvider` implementation that resolves pages via `IServiceProvider`

Internal Types

None.

Module: Wpf.Ui.Tray

NuGet: WPF-UI.Tray TFMs: net10.0-windows, net9.0-windows, net8.0-windows, net481, net472, net462 Dependencies: Wpf.Ui, System.Drawing.Common

Public Types

Type	Kind	Description
`INotifyIconService`	Interface	Service interface for tray icon management
`NotifyIconService`	Class	`INotifyIconService` implementation
`NotifyIcon`	Control	WPF control for declarative tray icon in XAML
`RoutedNotifyIconEvent`	Delegate	Event delegate for tray icon interactions

Internal Types

Type	Kind	Description
`INotifyIcon`	Interface	Internal abstraction for tray icon operations
`TrayHandler`	Class	Shell32 `Shell_NotifyIcon` P/Invoke wrapper
`TrayManager`	Class	Tray icon lifecycle management
`TrayData`	Struct	Native tray icon data structure
`Hicon`	Struct	Icon handle wrapper
`NotifyIconEventHandler`	Delegate	Internal event handler
`InternalNotifyIconManager`	Class	Theme-aware tray icon management

Module: Wpf.Ui.SyntaxHighlight

NuGet: WPF-UI.SyntaxHighlight TFMs: net10.0-windows, net9.0-windows, net8.0-windows, net481, net472, net462 Dependencies: Wpf.Ui

Public Types

Type	Kind	Description
`CodeBlock`	Control	WPF control for syntax-highlighted code display
`SyntaxHighlightDictionary`	Markup Extension	XAML resource dictionary for syntax highlighting styles

Internal Types

Type	Kind	Description
`Highlighter`	Class	Regex-based syntax highlighting engine
`SyntaxLanguage`	Enum	Supported language identifiers

Module: Wpf.Ui.ToastNotifications

NuGet: WPF-UI.ToastNotifications TFMs: net10.0-windows, net9.0-windows, net8.0-windows, net481, net472, net462 Dependencies: None (standalone stub)

Public Types

Type	Kind	Description
`Toast`	Class	STUB — all methods throw `NotImplementedException`

Warning: This module is a placeholder with no implementation. See RECOMMENDATIONS.md — recommended to either implement or remove.

Module: Wpf.Ui.FlaUI

NuGet: WPF-UI.FlaUI TFMs: net10.0-windows, net9.0-windows, net8.0-windows, net481 Dependencies: FlaUI.Core

Public Types

Type	Kind	Description
`AutoSuggestBox`	Class	FlaUI automation element wrapper for `Wpf.Ui.Controls.AutoSuggestBox`

Module: Wpf.Ui.FontMapper

Type: Build-time console tool (not a distributable library) TFMs: net10.0 Dependencies: None

Public Types

None. This is a build tool that generates SymbolRegular and SymbolFilled enums from Fluent System Icons font JSON data. It is not referenced by other projects at runtime.

Cross-Module Interface Rules

Abstractions are the only shared contract. Modules that need to communicate must do so through Wpf.Ui.Abstractions interfaces.
Core library is the integration point. Only Wpf.Ui may depend on Win32 interop and WPF framework internals.
Satellite packages depend downward only. Tray and SyntaxHighlight depend on Core; they never depend on each other.
DI package depends on Abstractions only. Wpf.Ui.DependencyInjection must never take a dependency on Wpf.Ui to keep it lightweight.
Internal namespaces are not API surface. Types in Wpf.Ui.Interop and Wpf.Ui.Win32 are implementation details even though they are currently public.