// after navigate
async Task NavigateFromAsync(bool suspending)
{
var page = FrameFacade.Content as Page;
if (page != null)
{
// call viewmodel
var dataContext = page.DataContext as INavigable;
if (dataContext != null)
{
var pageState = FrameFacade.PageStateContainer(page.GetType());
await dataContext.OnSaveStateAsync(pageState, suspending);
dataContext.OnSaveState(pageState, suspending);
}
}
}
public void SaveNavigation()
{
if (CurrentPageType == null)
{
return;
}
var state = FrameFacade.PageStateContainer(GetType());
if (state == null)
{
throw new InvalidOperationException("State container is unexpectedly null");
}
state["CurrentPageType"] = CurrentPageType.AssemblyQualifiedName;
state["CurrentPageParam"] = SerializePageParam(CurrentPageParam);
state["NavigateState"] = FrameFacade?.GetNavigationState();
}
void NavigateTo(NavigationMode mode, object parameter)
{
parameter = DeserializePageParam(parameter);
LastNavigationParameter = parameter;
LastNavigationType = FrameFacade.Content.GetType().FullName;
if (mode == NavigationMode.New)
{
FrameFacade.ClearFrameState();
}
var page = FrameFacade.Content as Page;
if (page != null)
{
if (page.DataContext == null)
{
// to support dependency injection, but keeping it optional.
var viewmodel = BootStrapper.Current.ResolveForPage(page.GetType(), this);
if (viewmodel != null)
{
page.DataContext = viewmodel;
}
}
// call viewmodel
var dataContext = page.DataContext as INavigable;
if (dataContext != null)
{
// prepare for state load
dataContext.NavigationService = this;
dataContext.Dispatcher = WindowWrapper.Current(this)?.Dispatcher;
dataContext.SessionState = BootStrapper.Current.SessionState;
var pageState = FrameFacade.PageStateContainer(page.GetType());
dataContext.OnNavigatedTo(parameter, mode, pageState);
}
}
}
public bool RestoreSavedNavigation()
{
try
{
var state = FrameFacade.PageStateContainer(GetType());
if (state == null || !state.Any() || !state.ContainsKey("CurrentPageType"))
{
return(false);
}
FrameFacade.CurrentPageType = Type.GetType(state["CurrentPageType"].ToString());
FrameFacade.CurrentPageParam = DeserializePageParam(state["CurrentPageParam"]?.ToString());
FrameFacade.SetNavigationState(state["NavigateState"]?.ToString());
NavigateTo(NavigationMode.Refresh, FrameFacade.CurrentPageParam);
while (Frame.Content == null)
{
Task.Yield().GetAwaiter().GetResult();
}
AfterRestoreSavedNavigation?.Invoke(this, FrameFacade.CurrentPageType);
return(true);
}
catch { return(false); }
}