public void PopTo <T>() where T : class, IViewModel
{
var pagesToRemove = new List <Page>();
var upper = FormsNavigation.NavigationStack.Count;
// Loop through the nav stack backwards
for (int i = upper - 1; i >= 0; i--)
{
var currentPage = FormsNavigation.NavigationStack[i] as IViewFor;
// Stop the whole show if one of the pages isn't an IViewFor
if (currentPage == null)
{
return;
}
var strongTypedPaged = currentPage as IViewFor <T>;
// If we hit the view model type, break out
if (strongTypedPaged != null)
{
break;
}
// Finally - always add to the list
pagesToRemove.Add(currentPage as Page);
}
foreach (var item in pagesToRemove)
{
FormsNavigation.RemovePage(item);
}
}
/// <inheritdoc />
public async Task PushAsync(BaseNavigationViewModel viewModel, bool discardCurrent = false)
{
var currentPage = FormsNavigation.NavigationStack.LastOrDefault();
var view = InstantiateView(viewModel);
if (currentPage.BindingContext is INavigationAware navPrevious)
{
navPrevious.OnNavigatingFrom();
}
if (viewModel is INavigationAware navForward)
{
navForward.OnNavigatingTo();
}
await FormsNavigation.PushAsync((Page)view);
if (viewModel is INavigationAware navigated)
{
navigated.OnNavigatedTo();
}
if (discardCurrent)
{
FormsNavigation.RemovePage(currentPage);
}
}
public async Task ReplaceAsync(Type pageModelType, NavigationState navState)
{
var oldTopPage = TopPage;
await PushAsync(pageModelType, navState);
FormsNavigation.RemovePage(oldTopPage);
PrintNavigationStackDepth("ReplaceAsync");
}
/// <inheritdoc />
public async Task PushAsync(BaseNavigationViewModel viewModel, bool discardCurrent = false)
{
var currentPage = FormsNavigation.NavigationStack.LastOrDefault();
var view = InstantiateView(viewModel);
await FormsNavigation.PushAsync((Page)view);
if (discardCurrent && currentPage != null)
{
FormsNavigation.RemovePage(currentPage);
}
}
public async Task ReplaceRootAsync(Type pageModelType,
NavigationState navState = null)
{
var pageList = FormsNavigation.NavigationStack.ToList();
await PushAsync(pageModelType, navState);
// Clean up old pages
foreach (var page in pageList)
{
FormsNavigation.RemovePage(page);
}
PrintNavigationStackDepth("ReplaceRootAsync");
}
/// <inheritdoc />
public async Task PushAsync <T>(Action <T> initialize = null, bool discardCurrent = false) where T : BaseNavigationViewModel
{
T viewModel;
var currentPage = FormsNavigation.NavigationStack.LastOrDefault();
// Instantiate the view model & invoke the initialize method, if any
viewModel = Activator.CreateInstance <T>();
initialize?.Invoke(viewModel);
await PushAsync(viewModel);
if (discardCurrent && currentPage != null)
{
FormsNavigation.RemovePage(currentPage);
}
}
public void RemovePage(NavigationViewModel viewModel)
{
var page = FormsNavigation.NavigationStack.FirstOrDefault(x => x.BindingContext == viewModel);
FormsNavigation.RemovePage(page);
}
