VRT.Mvvm.Navigation 1.0.1

VRT.Mvvm

Shared, toolkit-agnostic MVVM navigation core for .NET applications (WinForms, WPF, MAUI, and similar hosts).

Packages

<PackageReference Include="VRT.Mvvm.Navigation" Version="*" />

Features

• Navigate by ViewModel type via a single INavigationService entrypoint
• Session View+ViewModel cache with suspend/dispose (INavigationWorkspace)
• Explicit View ↔ ViewModel registration (IComponentLocator / DI helpers)
• Hosts display views via toolkit-specific IRoutingHandler.ShowView(object view)
• Lightweight NavigationResult / NavigationResult<T> with internal Bind / Tap / Map
• Roslyn generators: AddMvvmComponents and partial ViewModel properties for IViewFor<T>

Requirements

• .NET 10 (library targets net10.0)
• Microsoft.Extensions.DependencyInjection.Abstractions (transitive)
• Host app typically uses Microsoft.Extensions.DependencyInjection

Quick start

using Microsoft.Extensions.DependencyInjection;
using VRT.Mvvm.Navigation;
using VRT.Mvvm.Navigation.Abstractions;

var services = new ServiceCollection();
services.AddNavigation();
// Manual mappings, or generated for all IViewFor<> in this assembly:
// services.AddNavigationComponent<HomeView, HomeViewModel>();
services.AddMvvmComponents(); // from source generator (ships with the NuGet package)

await using var provider = services.BuildServiceProvider();

var navigation = provider.GetRequiredService<INavigationService>();
// Host implements IRoutingHandler and registers itself:
// navigation.RegisterRoutingHandler(this);

await navigation.NavigateToAsync<HomeViewModel>(
    configure: vm => { /* optional setup */ },
    cacheView: true);

Terminology

Host responsibilities

1. Implement IRoutingHandler.ShowView(object view) to place the view in the UI (content control, panel, frame, …).
2. Call INavigationService.RegisterRoutingHandler(this) on startup (do not register the host in DI if that creates a cycle with INavigationService).
3. Register navigable pairs via AddMvvmComponents() (generated) and/or AddNavigationComponent<TView, TViewModel>().

Views and ViewModels

Views should be partial and implement IViewFor<TViewModel>:

• One IViewFor<T> → generator emits public TViewModel? ViewModel { get; set; }
• Several IViewFor<> on the same view → generator emits explicit TViewModel? IViewFor<TViewModel>.ViewModel properties (avoids name/type clash)
• Hand-written ViewModel members are left as-is

Optional ISuspendable pauses inactive screens; IDisposable is honored when the workspace discards or evicts a pair.

Navigation injects the active ViewModel via public DataContext / ViewModel when assignable, and via matching IViewFor<T> (including explicit implementations).

Cache behavior

Session cache is keyed by ViewModel type (one View class may back multiple ViewModels).

Call INavigationWorkspace.Clear() on logout (or similar) to dispose all cached screens.

Multi-project with Views

Each project that defines IViewFor<> views and should get generated AddMvvmComponents / ViewModel properties must compile with the generator (via VRT.Mvvm.Navigation or VRT.Mvvm.Navigation.Generators). Call AddMvvmComponents() per assembly that contains views.

Design notes

• Core has no WPF / WinForms / MAUI types.
• No MediatR / CSharpFunctionalExtensions dependency.
• Source generators ship with the main package; optional standalone Generators package for advanced layouts.

License

MIT — see LICENSE.txt.