private bool InnerNavigate(PageStackEntry entry, NavigationMode mode)
{
try
{
// Navigating
var navigatingFromArgs = new NavigatingCancelEventArgs(
mode,
entry.NavigationTransitionInfo,
entry.Parameter,
entry.SourcePageType
);
Navigating?.Invoke(this, navigatingFromArgs);
if (navigatingFromArgs.Cancel)
{
// Frame canceled
OnNavigationStopped(entry, mode);
return(false);
}
CurrentEntry?.Instance.OnNavigatingFrom(navigatingFromArgs);
if (navigatingFromArgs.Cancel)
{
// Page canceled
OnNavigationStopped(entry, mode);
return(false);
}
// Navigate
var previousEntry = CurrentEntry;
CurrentEntry = entry;
if (mode == NavigationMode.New)
{
// Doing this first allows CurrentEntry to reuse existing page if pooling is enabled
ReleasePages(ForwardStack);
}
if (CurrentEntry.Instance == null)
{
var page = CreatePageInstanceCached(entry.SourcePageType);
if (page == null)
{
return(false);
}
page.Frame = this;
CurrentEntry.Instance = page;
}
Content = CurrentEntry.Instance;
if (IsNavigationStackEnabled)
{
switch (mode)
{
case NavigationMode.New:
ForwardStack.Clear();
if (previousEntry != null)
{
BackStack.Add(previousEntry);
}
break;
case NavigationMode.Back:
ForwardStack.Add(previousEntry);
BackStack.Remove(CurrentEntry);
break;
case NavigationMode.Forward:
BackStack.Add(previousEntry);
ForwardStack.Remove(CurrentEntry);
break;
case NavigationMode.Refresh:
break;
}
}
// Navigated
var navigationEvent = new NavigationEventArgs(
CurrentEntry.Instance,
mode,
entry.NavigationTransitionInfo,
entry.Parameter,
entry.SourcePageType,
null
);
previousEntry?.Instance.OnNavigatedFrom(navigationEvent);
CurrentEntry.Instance.OnNavigatedTo(navigationEvent);
Navigated?.Invoke(this, navigationEvent);
VisualTreeHelper.CloseAllPopups();
return(true);
}
catch (Exception exception)
{
NavigationFailed?.Invoke(this, new NavigationFailedEventArgs(entry.SourcePageType, exception));
if (NavigationFailed == null)
{
Application.Current.RaiseRecoverableUnhandledException(new InvalidOperationException("Navigation failed", exception));
}
return(false);
}
}
private bool InnerNavigate(PageStackEntry entry, NavigationMode mode)
{
try
{
// Navigating
var navigatingFromArgs = new NavigatingCancelEventArgs(
mode,
entry.NavigationTransitionInfo,
entry.Parameter,
entry.SourcePageType
);
Navigating?.Invoke(this, navigatingFromArgs);
CurrentEntry?.Instance.OnNavigatingFrom(navigatingFromArgs);
if (navigatingFromArgs.Cancel)
{
NavigationStopped?.Invoke(this, new NavigationEventArgs(
entry.Instance,
mode,
entry.NavigationTransitionInfo,
entry.Parameter,
entry.SourcePageType,
null
));
return(false);
}
// Navigate
var previousEntry = CurrentEntry;
CurrentEntry = entry;
if (CurrentEntry.Instance == null)
{
var page = CreatePageInstance(entry.SourcePageType);
if (page == null)
{
return(false);
}
page.Frame = this;
CurrentEntry.Instance = page;
}
Content = CurrentEntry.Instance;
switch (mode)
{
case NavigationMode.New:
ForwardStack.Clear();
if (previousEntry != null)
{
BackStack.Add(previousEntry);
}
break;
case NavigationMode.Back:
ForwardStack.Add(previousEntry);
BackStack.Remove(CurrentEntry);
break;
case NavigationMode.Forward:
BackStack.Add(previousEntry);
ForwardStack.Remove(CurrentEntry);
break;
case NavigationMode.Refresh:
break;
}
// Navigated
var navigationEvent = new NavigationEventArgs(
CurrentEntry.Instance,
mode,
entry.NavigationTransitionInfo,
entry.Parameter,
entry.SourcePageType,
null
);
previousEntry?.Instance.OnNavigatedFrom(navigationEvent);
CurrentEntry.Instance.OnNavigatedTo(navigationEvent);
Navigated?.Invoke(this, navigationEvent);
VisualTreeHelper.CloseAllPopups();
return(true);
}
catch (Exception exception)
{
NavigationFailed?.Invoke(this, new NavigationFailedEventArgs(entry.SourcePageType, exception));
return(false);
}
}