feat: adding Forced option for ViewModelLocationBehavior

src/Maui/Prism.Maui/Mvvm/ViewModelLocator.cs

@@ -1,4 +1,4 @@
-namespace Prism.Mvvm;
+namespace Prism.Mvvm;
 
 /// <summary>
 /// This class defines the attached property and related change handler that calls the <see cref="ViewModelLocationProvider"/>.
@@ -9,7 +9,15 @@ public static class ViewModelLocator
     /// Instructs Prism whether or not to automatically create an instance of a ViewModel using a convention, and assign the associated View's <see cref="BindableObject.BindingContext"/> to that instance.
     /// </summary>
     public static readonly BindableProperty AutowireViewModelProperty =
-        BindableProperty.CreateAttached("AutowireViewModel", typeof(ViewModelLocatorBehavior), typeof(ViewModelLocator), ViewModelLocatorBehavior.Automatic);
+        BindableProperty.CreateAttached("AutowireViewModel", typeof(ViewModelLocatorBehavior), typeof(ViewModelLocator), ViewModelLocatorBehavior.Automatic, propertyChanged: OnViewModelLocatorBehaviorChanged);
+
+    private static void OnViewModelLocatorBehaviorChanged(BindableObject bindable, object oldValue, object newValue)
+    {
+        if (newValue is ViewModelLocatorBehavior behavior && behavior == ViewModelLocatorBehavior.Forced)
+        {
+            Autowire(bindable);
+        }
+    }
 
     internal static readonly BindableProperty ViewModelProperty =
         BindableProperty.CreateAttached("ViewModelType",

src/Maui/Prism.Maui/Mvvm/ViewModelLocatorBehavior.cs

@@ -1,7 +1,33 @@
 namespace Prism.Mvvm;
 
+/// <summary>
+/// Defines the behavior that the <see cref="ViewModelLocator"/> should use.
+/// </summary>
 public enum ViewModelLocatorBehavior
 {
+    /// <summary>
+    /// The ViewModel will be lazily loaded by the Page/Region Navigation Services
+    /// or the DialogService.
+    /// </summary>
+    /// <remarks>
+    /// This is the default and recommended value for the ViewModelLocator. This will
+    /// allow the View to be fully initialized and ensure that the proper ViewModel is
+    /// resolved based on the route name.
+    /// </remarks>
     Automatic,
-    Disabled
+
+    /// <summary>
+    /// This will disable Prism's automatic ViewModel Location
+    /// </summary>
+    Disabled,
+
+    /// <summary>
+    /// This is not recommended for most situations
+    /// </summary>
+    /// <remarks>
+    /// This is likely to cause breaks in the Container Scoping. It is recommended that
+    /// you allow Prism Page/Region Navigation Services or the Dialog Service properly
+    /// resolve the ViewModel.
+    /// </remarks>
+    Forced
 }

src/Maui/Prism.Maui/Navigation/Xaml/Navigation.cs

@@ -1,4 +1,4 @@
-using System.ComponentModel;
+using System.ComponentModel;
 using Prism.Common;
 using Prism.Navigation.Internals;
 
@@ -154,6 +154,15 @@ public static IContainerProvider GetContainerProvider(this BindableObject bindab
         {
             if (page.Parent is FlyoutPage flyout && flyout.Flyout == page)
                 return flyout.GetContainerProvider();
+
+            if (Mvvm.ViewModelLocator.GetAutowireViewModel(page) == Mvvm.ViewModelLocatorBehavior.Forced)
+            {
+                container = ContainerLocator.Container.CreateScope();
+                var accessor = container.Resolve<IPageAccessor>();
+                accessor.Page = page;
+                SetContainerProvider(page, container);
+                return container;
+            }
         }
         else if (bindable is Element element && element.Parent is not null)
             return GetContainerProvider(element.Parent);

tests/Maui/Prism.DryIoc.Maui.Tests/Fixtures/Navigation/NavigationTests.cs

@@ -40,6 +40,23 @@ public void PagesInjectScopedInstanceOfIPageAccessor(string uri)
         }
     }
 
+    [Fact]
+    public async Task ViewModelLocator_Forced_SetsContainer_ResolvedViewModel()
+    {
+        var mauiApp = CreateBuilder(prism => prism
+            .RegisterTypes(c => c.RegisterForNavigation<ForcedView>())
+            .CreateWindow("ForcedView"))
+            .Build();
+        var window = GetWindow(mauiApp);
+
+        Assert.IsType<ForcedView>(window.Page);
+        Assert.IsType<ForcedViewModel>(window.Page.BindingContext);
+
+        var viewModel = (ForcedViewModel)window.Page.BindingContext;
+        Assert.NotNull(viewModel.Page);
+        Assert.IsType<ForcedView>(viewModel.Page);
+    }
+
     [Fact]
     public async Task AddsPageFromRelativeURI()
     {

tests/Maui/Prism.DryIoc.Maui.Tests/Mocks/ViewModels/ForcedViewModel.cs

@@ -0,0 +1,15 @@
+using Prism.Common;
+
+namespace Prism.DryIoc.Maui.Tests.Mocks.ViewModels;
+
+internal class ForcedViewModel
+{
+    public ForcedViewModel(IPageAccessor accessor)
+    {
+        _accessor = accessor;
+    }
+
+    private readonly IPageAccessor _accessor;
+
+    public Page Page => _accessor.Page;
+}

tests/Maui/Prism.DryIoc.Maui.Tests/Mocks/Views/ForcedView.cs

@@ -0,0 +1,9 @@
+namespace Prism.DryIoc.Maui.Tests.Mocks.Views;
+
+internal class ForcedView : ContentPage
+{
+    public ForcedView()
+    {
+        ViewModelLocator.SetAutowireViewModel(this, ViewModelLocatorBehavior.Forced);
+    }
+}