/// <summary>
/// Called when the <c>Navigating</c> event is invoked.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="e">The <see cref="NavigatingCancelEventArgs"/> instance containing the event data.</param>
/// <remarks>
/// This method is public due to the fact that weak events are used. Otherwise, the navigation completed events
/// could not be handled (because we unsubscribed from the _rootFrame) when navigating away to prevent memory
/// leaks.
/// <para />
/// Please, do not call this method yourself, otherwise you can seriously ruin your apps.
/// </remarks>
public void OnNavigatingEvent(object sender, NavigatingCancelEventArgs e)
{
if (!CanHandleNavigation)
{
return;
}
var uriString = e.GetUriWithoutQueryInfo();
_hasNavigatedButNotNavigatedAway = false;
#if WINDOWS_PHONE
var uriWithoutParameters = GetUriWithoutParameters(_rootFrame.CurrentSource);
if (string.CompareOrdinal(uriWithoutParameters, _url) != 0)
{
return;
}
#endif
OnNavigating(e);
if (!e.Cancel && !HasHandledSaveAndCancelLogic)
{
if (NavigatingAwaySavesViewModel)
{
SaveAndCloseViewModel();
}
else
{
CancelAndCloseViewModel();
}
HasHandledSaveAndCancelLogic = true;
#if NETFX_CORE
//_rootFrame.Navigating -= OnNavigatingEvent;
//_rootFrame.Navigated -= OnNavigatedEvent;
#elif WINDOWS_PHONE
//_rootFrame.BackKeyPress -= OnBackKeyPress;
//_rootFrame.Navigating -= OnNavigatingEvent;
//_rootFrame.Navigated -= OnNavigatedEvent;
#elif SILVERLIGHT
_rootFrame.Navigating -= OnNavigatingEvent;
_rootFrame.Navigated -= OnNavigatedEvent;
#else
Application.Current.Navigating -= OnNavigatingEvent;
Application.Current.Navigated -= OnNavigatedEvent;
#endif
}
_navigationComplete = false;
}
/// <summary>
/// Tombstones the application.
/// </summary>
private void TombstoneIfRequired(NavigatingCancelEventArgs e)
{
if (_isTombstoned)
{
return;
}
var uriString = e.GetUriWithoutQueryInfo();
if (!uriString.StartsWith("app://external", StringComparison.InvariantCultureIgnoreCase))
{
return;
}
var viewModelAsViewModelBase = ViewModel as ViewModelBase;
if (viewModelAsViewModelBase != null)
{
Tombstoning.SafeInvoke(this);
switch (viewModelAsViewModelBase.TombstoningMode)
{
case TombstoningMode.Disabled:
break;
case TombstoningMode.Manual:
viewModelAsViewModelBase.PrepareForTombstoneStateInternal(PhoneApplicationService.Current.State);
break;
case TombstoningMode.Auto:
var tombstoneData = ((ViewModelBase)ViewModel).SerializeForTombstoning();
PhoneApplicationService.Current.State[TombstoneKey] = tombstoneData;
Log.Debug("Automatically created tombstone data with key '{0}'", TombstoneKey);
break;
}
Tombstoned.SafeInvoke(this);
}
_isTombstoned = true;
}
