/// <summary>
/// Returns the currently visible ViewModel.
/// </summary>
/// <param name="item">The routing state.</param>
/// <returns>The matching ViewModel or null if none exists.</returns>
public static IRoutableViewModel GetCurrentViewModel(this RoutingState item)
{
if (item == null)
{
throw new System.ArgumentNullException(nameof(item));
}
return(item.NavigationStack.LastOrDefault());
}
/// <summary>
/// Creates a ReactiveCommand which will, when invoked, navigate to the
/// type specified by the type parameter via looking it up in the
/// Dependency Resolver.
/// </summary>
public static IReactiveCommand NavigateCommandFor <T>(this RoutingState This)
where T : IRoutableViewModel, new()
{
var ret = new ReactiveCommand <object>(This.Navigate.CanExecuteObservable, x => Observable.Return(x));
ret.Select(_ => (IRoutableViewModel)Locator.Current.GetService <T>() ?? new T()).InvokeCommand(This.Navigate);
return(ret);
}
/// <summary>
/// Locate the first ViewModel in the stack that matches a certain Type.
/// </summary>
/// <typeparam name="T">The view model type.</typeparam>
/// <param name="item">The routing state.</param>
/// <returns>The matching ViewModel or null if none exists.</returns>
public static T FindViewModelInStack <T>(this RoutingState item)
where T : IRoutableViewModel
{
if (item == null)
{
throw new System.ArgumentNullException(nameof(item));
}
return(item.NavigationStack.Reverse().OfType <T>().FirstOrDefault());
}
/// <summary>
/// Returns the currently visible ViewModel
/// </summary>
public static IRoutableViewModel GetCurrentViewModel(this RoutingState This)
{
return(This.NavigationStack.LastOrDefault());
}
/// <summary>
/// Locate the first ViewModel in the stack that matches a certain Type.
/// </summary>
/// <returns>The matching ViewModel or null if none exists.</returns>
public static T FindViewModelInStack <T>(this RoutingState This)
where T : IRoutableViewModel
{
return(This.NavigationStack.Reverse().OfType <T>().FirstOrDefault());
}
