// Return a collection of key-value pairs to store in the application state.
public List <KeyValuePair <string, object> > SaveState()
{
if (App.ViewModel.IsDataLoaded)
{
List <KeyValuePair <string, object> > stateList
= new List <KeyValuePair <string, object> >();
// Create a new dictionary to store binding collections.
var collections = new Dictionary <string, object>();
// Add the current Titles binding collection.
collections["Titles"] = App.ViewModel.Titles;
// Store the current context and binding collections in the view model state.
stateList.Add(new KeyValuePair <string, object>(
"DataServiceState", DataServiceState.Serialize(_context, collections)));
stateList.Add(new KeyValuePair <string, object>("CurrentPage", CurrentPage));
stateList.Add(new KeyValuePair <string, object>("TotalCount", TotalCount));
return(stateList);
}
else
{
return(null);
}
}
// Saves the current state to persisted storage.
public DataServiceState SaveState()
{
// Create a new dictionary to store binding collections.
var collections = new Dictionary <string, object>();
// Add the current Titles binding collection.
collections.Add("Photos", App.ViewModel.Photos);
// Add the current context and binding collections to the list.
return(DataServiceState.Save(App.ViewModel._context, collections));
}
public void RestoreState(IDictionary <string, object> storedState)
{
object stateAsString;
Dictionary <string, object> collections;
if (storedState.TryGetValue("DataServiceState", out stateAsString))
{
var dsState = DataServiceState.Deserialize((string)stateAsString);
this._context = dsState.Context as OratorEntities;
collections = dsState.RootCollections;
if (collections != null)
{
if (collections.ContainsKey("Events"))
{
this.Events = collections["Events"] as DataServiceCollection <Event>;
if (collections.ContainsKey("Sessions"))
{
this.Sessions = collections["Sessions"] as DataServiceCollection <Session>;
if (collections.ContainsKey("Speakers"))
{
this.Speakers = collections["Speakers"] as DataServiceCollection <SessionSpeaker>;
}
if (collections.ContainsKey("SessionFiles"))
{
this.SessionFiles = collections["SessionFiles"] as DataServiceCollection <SessionFile>;
}
}
}
}
// Restore entity properties from the stored URI.
_context.TryGetEntity <Session>(storedState["CurrentSession"] as Uri, out _currentSession);
_context.TryGetEntity <Event>(storedState["CurrentEvent"] as Uri, out _currentEvent);
_context.TryGetEntity <SessionSpeaker>(storedState["SingleSpeaker"] as Uri, out _singleSpeaker);
// Restore other non-entity properties.
this.TotalSessionCount = (int)storedState["TotalSessionCount"];
this.Message = (string)storedState["Message"];
this.CountMessage = (string)storedState["CountMessage"];
this.QueryInfo = (QueryHelper)storedState["QueryInfo"];
this.SessionCategories = (List <string>)storedState["SessionCategories"];
this.SessionDates = (List <string>)storedState["SessionDates"];
this.SessionTracks = (List <string>)storedState["SessionTracks"];
}
}
void Deserialize(string contextDataString)
{
var contextData = DataServiceState.Deserialize(contextDataString);
context = contextData.Context as OrlandoCodeCampEntities;
var collections = contextData.RootCollections;
Announcements = GetCollection <Announcement>(collections, "announcements");
Sessions = GetCollection <Session>(collections, "sessions");
Tracks = GetCollection <Track>(collections, "tracks");
Speakers = GetCollection <Person>(collections, "speakers");
Sponsors = GetCollection <Sponsor>(collections, "sponsors");
Timeslots = GetCollection <Timeslot>(collections, "timeslots");
IsDataLoaded = true;
}
string Serialize()
{
if (!IsDataLoaded)
{
return(null);
}
var collections = new Dictionary <string, object>();
collections["announcements"] = Announcements;
collections["sessions"] = Sessions;
collections["tracks"] = Tracks;
collections["speakers"] = Speakers;
collections["sponsors"] = Sponsors;
collections["timeslots"] = Timeslots;
return(DataServiceState.Serialize(context, collections));
}
// Return a string serialization of the application state.
public string SaveState()
{
if (App.ViewModel.IsDataLoaded)
{
// Create a new dictionary to store binding collections.
var collections = new Dictionary <string, object>();
// Add the current Customers binding collection.
collections["Customers"] = Customers;
// Return the serialized context and binding collections.
return(DataServiceState.Serialize(_context, collections));
}
else
{
return(string.Empty);
}
}
// Restores the view model state from the supplied state serialization.
public void RestoreState(string appState)
{
// Create a dictionary to hold any stored binding collections.
Dictionary <string, object> collections;
if (!string.IsNullOrEmpty(appState))
{
// Deserialize the DataServiceState object.
DataServiceState state
= DataServiceState.Deserialize(appState);
// Restore the context and binding collections.
var context = state.Context as NorthwindEntities;
collections = state.RootCollections;
// Get the binding collection of Customer objects.
DataServiceCollection <Customer> customers
= collections["Customers"] as DataServiceCollection <Customer>;
// Initialize the application with stored data.
App.ViewModel.LoadData(context, customers);
}
}
// Restores the view model state from the supplied state dictionary.
public void RestoreState(IDictionary <string, object> dictionary)
{
// Create a dictionary to hold any stored binding collections.
object titles;
object stateAsString;
if (dictionary.TryGetValue("DataServiceState", out stateAsString))
{
// Rehydrate the DataServiceState object from the serialization.
DataServiceState state =
DataServiceState.Deserialize((string)stateAsString);
if (state.RootCollections.TryGetValue("Titles", out titles))
{
// Initialize the application with data from the DataServiceState.
App.ViewModel.LoadData((NetflixCatalog)state.Context,
(DataServiceCollection <Title>)titles);
// Restore other view model data.
_currentPage = (int)dictionary["CurrentPage"];
_totalCount = (int)dictionary["TotalCount"];
}
}
}
public List <KeyValuePair <string, object> > SaveState()
{
Uri storageUri;
List <KeyValuePair <string, object> > stateList = new List <KeyValuePair <string, object> >();
Dictionary <string, object> collections = new Dictionary <string, object>();
if (this.Events != null)
{
collections.Add("Events", this.Events);
if (this.Sessions != null)
{
collections.Add("Sessions", this.Sessions);
if (this.Speakers != null)
{
collections.Add("Speakers", this.Speakers);
}
if (this.SessionFiles != null)
{
collections.Add("SessionFiles", this.SessionFiles);
}
}
}
// Add the DataServiceState to the collection.
stateList.Add(new KeyValuePair <string, object>("DataServiceState", DataServiceState.Serialize(_context, collections)));
// We can't store entities directly, so store the URI instead.
if (CurrentSession != null && _context.TryGetUri(CurrentSession, out storageUri))
{
// Store the URI of the CurrentSession.
stateList.Add(new KeyValuePair <string, object>("CurrentSession", storageUri));
}
if (CurrentEvent != null && _context.TryGetUri(CurrentEvent, out storageUri))
{
// Store the URI of the CurrentEvent.
stateList.Add(new KeyValuePair <string, object>("CurrentEvent", storageUri));
}
if (SingleSpeaker != null && _context.TryGetUri(SingleSpeaker, out storageUri))
{
// Store the URI of the Speaker.
stateList.Add(new KeyValuePair <string, object>("SingleSpeaker", storageUri));
}
// Add other non-entity binding properties to the collection.
stateList.Add(new KeyValuePair <string, object>("TotalSessionCount", TotalSessionCount));
stateList.Add(new KeyValuePair <string, object>("Message", Message));
stateList.Add(new KeyValuePair <string, object>("CountMessage", CountMessage));
stateList.Add(new KeyValuePair <string, object>("QueryInfo", QueryInfo));
stateList.Add(new KeyValuePair <string, object>("SessionCategories", SessionCategories));
stateList.Add(new KeyValuePair <string, object>("SessionDates", SessionDates));
stateList.Add(new KeyValuePair <string, object>("SessionLevels", SessionLevels));
stateList.Add(new KeyValuePair <string, object>("SessionTracks", SessionTracks));
return(stateList);
}
