private void ProcessSnapshots( Breadcrumb breadcrumb )
{
if( _navigationSnapshots.Count > 0 )
{
var snapshots = _navigationSnapshots.Where( snapshot => snapshot.Breadcrumb.Equals( breadcrumb ) ).ToList();
foreach( var snapshot in snapshots )
{
if( snapshot.Guard != null )
{
snapshot.Guard( snapshot.Tag );
}
_navigationSnapshots.Remove( snapshot );
}
}
}
private bool RestoreBreadcrumbs( bool clearOnSuccess = true )
{
if( !ApplicationData.Current.RoamingSettings.Values.ContainsKey( "Breadcrumbs" ) )
{
return false;
}
var unwind = new Stack<Breadcrumb>();
string state;
try
{
var history = (string) ApplicationData.Current.RoamingSettings.Values["Breadcrumbs"];
using( var stream = new MemoryStream( Convert.FromBase64String( history ) ) )
{
var reader = new BinaryReader( stream );
state = reader.ReadString();
var count = reader.ReadInt32();
while( count-- > 0 )
{
var pageTypeName = reader.ReadString();
var hasParameters = reader.ReadBoolean();
var pageType = Type.GetType( pageTypeName );
XParameters parameters = null;
if( hasParameters )
{
parameters = XParametersSerializer.Deserialize( reader );
}
var breadcrumb = new Breadcrumb( pageType, parameters );
unwind.Push( breadcrumb );
}
}
if( unwind.Count == 0 )
{
return false;
}
}
catch( IOException )
{
return false;
}
foreach( var bc in unwind )
{
_breadcrumbs.Push( bc );
}
IsUnwinding = true;
((WindowsRTApplication) Application.Current).RootFrame.SetNavigationState( state );
IsUnwinding = false;
if( clearOnSuccess )
{
ApplicationData.Current.RoamingSettings.Values["Breadcrumbs"] = null;
}
return true;
}
private void RootFrame_Navigated( object sender, NavigationEventArgs e )
{
if( !_initialized )
{
CompleteInitialization( e );
}
if( e.NavigationMode == NavigationMode.Back )
{
var breadcrumb = _breadcrumbs.Pop();
ProcessSnapshots( breadcrumb );
}
else if( e.NavigationMode == NavigationMode.New )
{
var breadcrumb = new Breadcrumb(e.SourcePageType, XParameters.Empty);
_breadcrumbs.Push(breadcrumb);
//_breadcrumbs.Push(new Breadcrumb(e.SourcePageType, e.Parameter as XParameters));
// _breadcrumbs.Push(new Breadcrumb(e.SourcePageType, XParameters.Empty));
}
}
