NavigateCommand & NavigateOnChanged

Generate DelegateCommand members that call IRegionManager.RequestNavigate. The ViewModel must already expose an accessible IRegionManager field or property (constructor injection is typical). Generators do not add constructor parameters.

NavigateCommand

csharp

using Prism.Mvvm;
using Prism.Navigation.Regions; // Prism 9+
// using Prism.Regions;         // Prism 8 (platform assembly)
using Prism.SourceGenerators;

public partial class ShellViewModel : BindableBase
{
    private readonly IRegionManager _regionManager;

    public ShellViewModel(IRegionManager regionManager) => _regionManager = regionManager;

    [NavigateCommand(Region = "Content", Target = "Dashboard")]
    private void GoDashboard() { }
}

Generates GoDashboardCommand calling _regionManager.RequestNavigate("Content", "Dashboard").

Optional attribute properties: CommandName, RegionManagerMember.

NavigateOnChanged

Apply to the same field or partial property as [ObservableProperty]:

csharp

[ObservableProperty]
[NavigateOnChanged(Region = "Content", TargetMember = nameof(Key))]
public partial NavigationItem SelectedItem { get; set; }

Generates OnSelectedItemChanged that navigates when the property changes. TargetMember is evaluated on the new value (for example Key).

Prism 8 vs Prism 9 regions

Prism	`INavigationAware` / `IRegionManager` namespace
9+	`Prism.Navigation.Regions` (in Prism.Core for `IRegionManager`; `INavigationAware` may also come from the platform package)
8	`Prism.Regions` (in Prism.Wpf, Prism.Avalonia, etc.—not in Prism.Core alone)

[NavigationAware] picks the namespace present in the compilation. Region navigation generators use the same resolution.

Diagnostics

ID	When
PSG7001	No accessible `IRegionManager` member
PSG7002	`[NavigateCommand]` missing `Region`
PSG7003	`[NavigateCommand]` missing `Target`
PSG7004	`[NavigateOnChanged]` without `[ObservableProperty]`
PSG7005	`[NavigateOnChanged]` missing `TargetMember`

NavigateCommand & NavigateOnChanged ​