public Page1ViewModel(INavigator navigator, INavigationPath navigationPath)
{
_navigator = navigator;
MyUserControl1ViewModel = new MyUserControl1ViewModel(navigator);
MyUserControl2ViewModel = new MyUserControl2ViewModel(navigationPath);
}
private async Task <INavigationResult> NavigateAsync(
INavigationPath pageNavInfo,
NavigationTransitionInfo infoOverride)
{
_logger.Log($"{nameof(FrameFacade)}.{nameof(NavigateAsync)}({pageNavInfo})", Category.Info, Priority.Low);
return(await OrchestrateAsync(
parameters : pageNavInfo.Parameters,
mode : NavigationMode.New,
#pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
navigate : async() =>
#pragma warning restore CS1998 // Async method lacks 'await' operators and will run synchronously
{
/*
* To enable serialization of the frame's state using GetNavigationState,
* you must pass only basic types to this method, such as string, char,
* numeric, and GUID types. If you pass an object as a parameter, an entry
* in the frame's navigation stack holds a reference on the object until the
* frame is released or that entry is released upon a new navigation that
* diverges from the stack. In general, we discourage passing a non-basic
* type as a parameter to Navigate because it can’t be serialized when the
* application is suspended, and can consume more memory because a reference
* is held by the frame’s navigation stack to allow the application to go forward and back.
* https://docs.microsoft.com/en-us/uwp/api/Windows.UI.Xaml.Controls.Frame#Windows_UI_Xaml_Controls_Frame_Navigate_Windows_UI_Xaml_Interop_TypeName_System_Object_
*/
var parameter = pageNavInfo.QueryString;
return _frame.Navigate(
sourcePageType: pageNavInfo.View,
parameter: parameter,
infoOverride: infoOverride);
}));
}
public MyUserControl2ViewModel(INavigationPath navigationPath)
{
navigationPath.ListChanged += (s, a) =>
{
TaskInfo = "Taskinfo for list " + a;
};
}
public async Task Navigate(INavigationPath path)
{
// major problem here: the lock is not re-entrant, and navigating while inside a navigation will deadlock the thread (waiting for itself to exit)
// todo change navigation code to cancel old nav requests when a new one is started, instead of locking
using (await _navigationLock.LockAsync().ConfigureAwait(false)) {
// we give the navigation request to the current navigation context first, walking down the stack until we find a handler
for (var frame = _activeFrame; frame != null; frame = frame.Parent) {
var resolution = frame.Context.HandleNavigation(path);
if (resolution != null) {
await ExecuteNavigationAction(resolution).ConfigureAwait(false);
OnNavigated(new NavigationEventArgs(CurrentLocation));
break;
}
}
}
}
public bool EvaluateVisibility(INavigationPath currentPath)
{
return !(currentPath is HomePath) && !(currentPath is LoginPath);
}
public PathResolution(Func<INavigationPath, Task<INavigationContext>> handler, IEnumerable<INavigationPath> excessPath, INavigationPath matchingPath)
{
_handler = handler;
ExcessPath = excessPath;
MatchingPath = matchingPath;
}
public virtual PathResolution HandleNavigation(INavigationPath path)
{
return Binder.Resolve(path);
}
public Bootstrapper()
{
_navigationPath = new NavigationPath();
_navigator = new Navigator(_navigationPath);
}
public bool EvaluateVisibility(INavigationPath currentPath)
{
return true;
}
public Navigator(INavigationPath navigationPath)
{
_navigationPath = navigationPath;
}
public NavigationEventArgs(INavigationPath path)
{
Path = path;
}
