/// <summary>
/// Handles the navigation when we are moving TO a new view/viewmodel.
/// </summary>
/// <param name="view"></param>
/// <param name="viewModel"></param>
/// <param name="navMode"></param>
/// <param name="parameter"></param>
private void HandleOnNavigatingTo(FrameworkElement view, object viewModel, NavigationMode navMode, object parameter)
{
// See if the ViewModel participates in navigation-aware services.
INavigationAware navm = viewModel as INavigationAware;
if (navm != null)
{
IDictionary <string, object> stateDictionary = null;
if (StateManager != null)
{
string key = GenerateStateKey(PageNavigator.ViewModelKeyPrefix);
StateManager.LoadObject(key, viewModel);
stateDictionary = StateManager.GetDictionary(key, false);
}
navm.OnNavigatedTo(new NavigatedToEventArgs(navMode, parameter, stateDictionary));
}
// See if the VIEW participates in navigation-aware services.
INavigationAware naView = view as INavigationAware;
if (naView != null)
{
IDictionary <string, object> stateDictionary = null;
if (StateManager != null)
{
string key = GenerateStateKey(PageNavigator.PageKeyPrefix);
stateDictionary = StateManager.GetDictionary(key, false);
}
naView.OnNavigatedTo(new NavigatedToEventArgs(navMode, parameter, stateDictionary));
}
}
protected override void OnStart()
{
base.OnStart();
var navigationParam = Nav.GetAndRemoveParameter(Intent);
_navigationAwareVm?.OnNavigatedTo(navigationParam);
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
App.ActiveView = this;
var navParam = this.GetLastNavigationParameter();
_navigationAwareVm?.OnNavigatedTo(navParam);
SetupBindings();
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
INavigationAware vm = DataContext as INavigationAware;
if (vm != null)
{
vm.OnNavigatedTo(e.Parameter, e.NavigationMode);
}
base.OnNavigatedTo(e);
}
private void ExecuteSearch(string phrase)
{
var searchBar = SearchBarService.Current;
if (searchBar != null)
{
UriQuery query = new UriQuery(searchBar.Parameters.ToString());
query.Add(SearchBar.ValueParameter, phrase);
query.Add(SearchBar.IsFromSearchBarParameter, "true");
IRegion viewRegion = RegionManager.Regions[AppRegions.ViewRegion];
IRegionNavigationService navigation = viewRegion.NavigationService;
if (navigation.Journal.CurrentEntry != null)
{
if (navigation.Journal.CurrentEntry.Uri.OriginalString.StartsWith(searchBar.NavigationUri.OriginalString))
{
INavigationAware navAware = null;
var activeView = viewRegion.ActiveViews.FirstOrDefault();
if (activeView is INavigationAware)
{
navAware = activeView as INavigationAware;
}
else
{
FrameworkElement element = activeView as FrameworkElement;
if (element != null && element.DataContext is INavigationAware)
{
navAware = element.DataContext as INavigationAware;
}
}
if (navAware != null)
{
navAware.OnNavigatedFrom(new NavigationContext(navigation,
navigation.Journal.CurrentEntry.Uri));
navAware.OnNavigatedTo(new NavigationContext(navigation,
new Uri(
searchBar.NavigationUri.ToString() + query,
UriKind.RelativeOrAbsolute)));
return;
}
}
}
RegionManager.RequestNavigate(AppRegions.ViewRegion, searchBar.NavigationUri.ToString() + query);
}
}
private void NotifyOnNavigatedTo(object parameter)
{
FrameworkElement contentElement = frame.Content as FrameworkElement;
if (contentElement == null)
{
return;
}
INavigationAware navigationAwareContext = contentElement.DataContext as INavigationAware;
if (navigationAwareContext != null)
{
navigationAwareContext.OnNavigatedTo(parameter);
}
}
void InvokeOnNavigatedTo(object item, NavigationContext navigationContext)
{
var navigationAwareItem = item as INavigationAware;
if (navigationAwareItem != null)
{
navigationAwareItem.OnNavigatedTo(navigationContext);
}
FrameworkElement frameworkElement = item as FrameworkElement;
if (frameworkElement != null)
{
INavigationAware navigationAwareDataContext = frameworkElement.DataContext as INavigationAware;
if (navigationAwareDataContext != null)
{
navigationAwareDataContext.OnNavigatedTo(navigationContext);
}
}
}
private async Task <NavigationResult> HandleViewModelNavigation(INavigationAware fromPageVM, INavigationAware toPageVM, INavigationParameters parameters)
{
if (fromPageVM != null)
{
try
{
fromPageVM.OnNavigatedFrom(parameters);
}
catch (Exception ex)
{
return(new NavigationResult()
{
IsSuccess = false, Exception = ex
});
}
}
if (toPageVM != null)
{
try
{
toPageVM.OnNavigatingTo(parameters);
toPageVM.OnNavigatedTo(parameters);
await toPageVM.OnNavigatedToAsync(parameters);
}
catch (Exception ex)
{
return(new NavigationResult()
{
IsSuccess = false, Exception = ex
});
}
}
return(new NavigationResult()
{
IsSuccess = true
});
}
/// <summary>
/// Called when the implementer has been navigated to.
/// </summary>
/// <param name="args">Provides data for navigation methods and event handlers that cannot cancel the navigation request.</param>
private void NavigatedTo(NavigationEventArgs args)
{
if(previousPage != null)
previousPage.OnNavigatedFrom(args);
previousPage = GetNavigationAware(args.Content);
if (previousPage == null) return;
previousPage.OnNavigatedTo(args);
}
