public sealed class NavigationRegion<TContent> : INavigationRegion, INotifyPropertyChanged where TContent : classOne navigation region: a stack of typed entries whose top is NavigationRegion.Current. State changes commit in one model turn and raise NavigationRegion.PropertyChanged inside that turn.
Type parameters
TContentThe content type presented by the region.
Remarks
Operations throw only for argument errors and ownership violations; every navigation outcome is returned as a NavigationResult. Called from inside a model turn, an operation is admitted without blocking and continues on the thread pool; do not block on it there.
Properties
CanGoBack
public bool CanGoBack { get; }Gets whether a retained entry exists to go back to.
Current
public TContent? Current { get; }Gets the current content, or null when the region is empty.
CurrentEntry
public NavigationEntry<TContent>? CurrentEntry { get; }Gets the current entry, or null when the region is empty.
History
public IReadOnlyList<NavigationEntry<TContent>> History { get; }Gets the retained entries below the current entry, from bottom to top.
IsTransitioning
public bool IsTransitioning { get; }Gets whether a transition of this region is in flight.
Methods
BackAsync
public ValueTask<NavigationResult<TContent>> BackAsync(NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Retires the current entry and resumes the top retained entry.
BackToAsync
public ValueTask<NavigationResult<TContent>> BackToAsync(NavigationEntryId entry, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Retires every entry above entry and resumes it.
ClearAsync
public ValueTask<NavigationResult<TContent>> ClearAsync(NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Retires every entry. The region becomes empty.
ClearHistoryAsync
public ValueTask<NavigationResult<TContent>> ClearHistoryAsync(NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Retires every retained entry. The current entry stays.
PushAsync
public ValueTask<NavigationResult<TContent>> PushAsync(INavigationTarget<TContent> target, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Pushes a new entry. The current entry is retained.
PushAsync
public ValueTask<NavigationResult<TContent>> PushAsync<TViewModel>(NavigationRequestOptions? options = null, CancellationToken cancellationToken = default) where TViewModel : class, TContentPushes a new TViewModel that the navigator constructs and owns, like NavigationRegion.PushAsync with NavigationTarget.Create.
Type parameters
TViewModelThe content type to construct; its constructor parameters come from the entry's service provider.
PushAsync
public ValueTask<NavigationResult<TContent>> PushAsync<TViewModel, TInput>(TInput input, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default) where TViewModel : class, TContent, INavigationInitialize<TInput>Pushes a new TViewModel that the navigator constructs, owns and initializes with input, like NavigationTarget.Create.
Type parameters
TViewModelThe content type to construct; its constructor parameters come from the entry's service provider.
TInputThe input type.
Parameters
inputThe input passed to
INavigationInitialize.InitializeAsync.optionsThe request's options.
cancellationTokenCancels the request before it commits.
PushForResult
public NavigationResultRequest<TContent, TResult> PushForResult<TResult>(INavigationTarget<TContent> target, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Pushes a new entry like NavigationRegion.PushAsync and waits for a typed result from it. The entry returns its result with NavigationEntryContext.CompleteAsync, which goes back from it; when it was pushed onto an empty region, the region becomes empty again.
Type parameters
TResultThe result type.
Remarks
NavigationResultRequest.Completion is dismissed when the push does not commit, when the entry retires without completing, and when the navigator closes. Cancelling cancellationToken before the commit gives the usual NavigationRejection.Cancelled outcome. After the commit it dismisses the request at once and goes back from the entry if it is still current; that back transition is not awaited, and a rejection or supersession of it is logged (1065, 1066). A departure guard that awaits a result in another region should pass its own token, so supersession and window close dismiss the request.
PushForResult
public NavigationResultRequest<TContent, TResult> PushForResult<TViewModel, TResult>(NavigationRequestOptions? options = null, CancellationToken cancellationToken = default) where TViewModel : class, TContentPushes a new TViewModel that the navigator constructs and owns, and waits for a typed result from it, like NavigationRegion.PushForResult with NavigationTarget.Create. For a target with input, pass NavigationTarget.Create to NavigationRegion.PushForResult.
Type parameters
TViewModelThe content type to construct; its constructor parameters come from the entry's service provider.
TResultThe result type.
ReplaceAsync
public ValueTask<NavigationResult<TContent>> ReplaceAsync(INavigationTarget<TContent> target, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Retires the current entry and makes a new entry current. History is unchanged.
ReplaceAsync
public ValueTask<NavigationResult<TContent>> ReplaceAsync<TViewModel>(NavigationRequestOptions? options = null, CancellationToken cancellationToken = default) where TViewModel : class, TContentReplaces the current entry with a new TViewModel that the navigator constructs and owns, like NavigationRegion.ReplaceAsync with NavigationTarget.Create.
Type parameters
TViewModelThe content type to construct; its constructor parameters come from the entry's service provider.
ReplaceAsync
public ValueTask<NavigationResult<TContent>> ReplaceAsync<TViewModel, TInput>(TInput input, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default) where TViewModel : class, TContent, INavigationInitialize<TInput>Replaces the current entry with a new TViewModel that the navigator constructs, owns and initializes with input.
Type parameters
TViewModelThe content type to construct; its constructor parameters come from the entry's service provider.
TInputThe input type.
Parameters
inputThe input passed to
INavigationInitialize.InitializeAsync.optionsThe request's options.
cancellationTokenCancels the request before it commits.
ResetAsync
public ValueTask<NavigationResult<TContent>> ResetAsync(INavigationTarget<TContent> target, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default)Retires every entry and makes a new entry the root.
ResetAsync
public ValueTask<NavigationResult<TContent>> ResetAsync<TViewModel>(NavigationRequestOptions? options = null, CancellationToken cancellationToken = default) where TViewModel : class, TContentRetires every entry and makes a new TViewModel, which the navigator constructs and owns, the root, like NavigationRegion.ResetAsync with NavigationTarget.Create.
Type parameters
TViewModelThe content type to construct; its constructor parameters come from the entry's service provider.
ResetAsync
public ValueTask<NavigationResult<TContent>> ResetAsync<TViewModel, TInput>(TInput input, NavigationRequestOptions? options = null, CancellationToken cancellationToken = default) where TViewModel : class, TContent, INavigationInitialize<TInput>Retires every entry and makes a new TViewModel, which the navigator constructs, owns and initializes with input, the root.
Type parameters
TViewModelThe content type to construct; its constructor parameters come from the entry's service provider.
TInputThe input type.
Parameters
inputThe input passed to
INavigationInitialize.InitializeAsync.optionsThe request's options.
cancellationTokenCancels the request before it commits.
Events
PropertyChanged
public event PropertyChangedEventHandler? PropertyChangedRaised inside a model turn after a commit, for NavigationRegion.Current, NavigationRegion.CurrentEntry, NavigationRegion.History, NavigationRegion.CanGoBack and NavigationRegion.IsTransitioning. Each handler is called separately; one that throws is logged and does not skip the others.