I have a C# Windows forms application that runs a Trivia game on an IRC channel, and keeps the questions it asks, and the Leaderboard (scores) in Classes that I serialize to XML to save between sessions. The issue I have been having is best described with the flow, so here it is:
User X Gets entry in Leaderboard class with a score of 1. Class is saved to XML, XML contains one entry for user X.
User Y gets entry in Leaderboard class with a score of 1. Class is saved to XML, XML contains duplicate entries for User X, and one entry for User Y.
After running it for a week with under 20 users, I hoped to be able to write a web backend in PHP to help me use the scores. XML file is 2 megabytes.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Runtime.Serialization;
namespace IRCTriviaBot
{
[Serializable()]
public class LeaderBoard
{
[Serializable()]
public class Pair
{
public string user;
public int score;
public Pair(string usr, int scr)
{
user = usr;
score = scr;
}
public Pair() { }
}
private static List<Pair> pairs = null;
public List<Pair> Pairs
{
get
{
if (pairs==null)
{
pairs = new List<Pair>();
}
return pairs;
}
}
public LeaderBoard()
{
}
public void newScore(string usr)
{
bool found = false;
for (int i = 0; i < Pairs.Count && !found; ++i)
{
if (Pairs[i].user==usr)
{
found = true;
Pairs[i].score++;
}
}
if (!found)
{
Pairs.Add(new Pair(usr, 1));
}
}
public int getScore(string usr)
{
bool found = false;
for (int i = 0; i < Pairs.Count && !found; ++i)
{
if (Pairs[i].user == usr)
{
return Pairs[i].score;
}
}
if (!found)
{
return 0;
}
return 0;
}
}
}
Here's where the serialization and deserialization happens.
void parseMessage(string message, string user = "")
{
if (message == "-startgame-")
{
if (!gameStarted)
{
gameStarted = true;
openScores();
startGame();
}
}
else if (message == "-hint-")
{
if (!hintGiven && gameStarted)
{
sendMessage("Here's a better hint: " + Form2.qa.Answers[curQ].Trim());
hintGiven = true;
}
}
else if (message == "-myscore-")
{
sendMessage(user + ", your score is: " + leaderB.getScore(user));
}
else if (message.ToLower() == Form2.qa.Answers[curQ].ToLower())
{
if (gameStarted)
{
sendMessage(user + " got it right! Virtual pat on the back!");
leaderB.newScore(user);
saveScores();
System.Threading.Thread.Sleep(2000);
startGame();
}
}
else if (message == "-quit-")
{
if (gameStarted)
{
sendMessage("Sorry to see you go! Have fun without me :'(");
gameStarted = false;
}
else
{
sendMessage("A game is not running.");
}
}
else
{
if (gameStarted)
{
//sendMessage("Wrong.");
}
}
}
void saveScores()
{
//Opens a file and serializes the object into it in binary format.
Stream stream = System.IO.File.Open("scores.xml", FileMode.Open);
XmlSerializer xmlserializer = new XmlSerializer(typeof(LeaderBoard));
//BinaryFormatter formatter = new BinaryFormatter();
xmlserializer.Serialize(stream, leaderB);
stream.Close();
}
void openScores()
{
Stream stream = System.IO.File.OpenRead("scores.xml");
XmlSerializer xmlserializer = new XmlSerializer(typeof(LeaderBoard));
//BinaryFormatter formatter = new BinaryFormatter();
leaderB = (LeaderBoard)xmlserializer.Deserialize(stream);
stream.Close();
}
I think this has to do with pairs being marked static. I don't believe the XmlSerializer will clear a list before adding elements to it, so every time you call openScores() you will create duplicate entries rather than overwrite existing ones.
In general, I've observed that serialization and global variables don't play well together. For this purpose, "global variables" includes private statics, singletons, monostate classes like this, and thread-local variables.
It also looks like there's some waffle here between using XML and binary serialization. They are completely different beasts. XML serialization looks only at a class's public properties, while binary serialization looks only at a class's instance fields. Also, XML serialization ignores the Serializable attribute.
Related
I am new to stackoverflow and to Unity3D, so I am sorry if I am doing things wrong.
So currently, I am making a puzzle game. It has 50 different levels.
I need for each of them, to save 3 or 4 variables.
For example, when level 1 is cleared, I want it to store (int)hitCounts, (bool)cleared, (int)bestHitCounts.
I don't wanna use playerPrefs, as I don't want it to be readable from outside the box. I want it be converted to a binary file.
here is what I have :
#1 : made a static class TGameDat
[System.Serializable]
public class TGameDat
{
public int tGameDatInt;
public bool tGameDatBool;
public int tSceneIndex;
public TGameDat (TPlayer player)
{
tGameDatInt = player.tInt;
tGameDatBool = player.tBool;
tSceneIndex = player.tScene;
}
}
#2 : then made Tplayer(monobehaviour)
public class TPlayer : MonoBehaviour
{
public int tInt = 0;
public bool tBool = false;
public int tScene;
public List<TPlayer> TestGameDatList = new List<TPlayer>();
private void Start()
{
TSceneMaker();
}
public void TSceneMaker()
{
tScene = SceneManager.GetActiveScene().buildIndex;
}
public void TNextScene()
{
SceneManager.LoadScene(tScene + 1);
}
public void TPreviousScene()
{
SceneManager.LoadScene(tScene - 1);
}
public void TSaveVariables()
{
TSave.TSavePlayer(this);
TestGameDatList.Add(this);
Debug.Log("saved");
Debug.Log(tInt + " " + tBool + " " + tScene);
}
public void TLoadVariables()
{
List<TGameDat> data = TSave.TLoadPlayer(this);
Debug.Log("loaded. data count = " + data.Count + " tSceneIndex " + tScene);
tInt = data[0].tGameDatInt;
tBool = data[0].tGameDatBool;
tScene = data[0].tSceneIndex;
}
}
#3 : finally I created a save and load system :
public static class TSave
{
public static void TSavePlayer (TPlayer player)
{
BinaryFormatter formatter = new BinaryFormatter();
List<TGameDat> data = new List<TGameDat>();
string path = Application.persistentDataPath + "/Tsave_" + player.tScene + ".fun";
if(File.Exists(path))
{
FileStream stream = File.Open(path, FileMode.Open);
data.Add(new TGameDat(player));
formatter.Serialize(stream, data);
stream.Close();
}
else
{
FileStream stream = File.Create(path);
data.Add(new TGameDat(player));
formatter.Serialize(stream, data);
stream.Close();
}
}
public static List<TGameDat> TLoadPlayer(TPlayer player)
{
string path = Application.persistentDataPath + "/Tsave_" + player.tScene + ".fun";
if(File.Exists(path))
{
BinaryFormatter formatter = new BinaryFormatter();
FileStream stream = File.Open(path, FileMode.Open);
List<TGameDat> data = new List<TGameDat>();
data = formatter.Deserialize(stream) as List<TGameDat>;
stream.Close();
return data;
}
else
{
Debug.LogError("Save file not found in " + path);
return null;
}
}
}
So, here are my problems :
1 : in the current situation, each scene compiles a binary file. So at the end, it will have a bunch of binary files piled up... Like 50, as I have 50 scenes... isn't it too many?
2 : of course I tried the make a single save file using List, and each level would come to add its own variable data in it.
But instead of adding the data, it would simply replace the previous data. Then there is always only 1 index in the List.
Therefore, when I load, the variables are from the last played level! And when I try to play another level after playing the first level, because there is only 1 index in the list, I get out of range error.
How shall I approach this?
sorry for the long long text!
thank you for your inputs!
first thing first, do you really need every level to have its own save data? Because if you only need to store the data between one level and another I would suggest you use some kind of PlayerState class that stores the data of the previous level.
But if you really need to store the data of every level then I'll recommend you using a dictionary rather than a simple list.
Here is an example of how I would do it
Note: I haven't tested this code yet!
SaveGameManager class
public string SavePath => Application.persistentDataPath + "/save.dat";
public static SaveGameManager Instance; // Singleton pattern
private Dictionary<string, TGameDat> gameData;
private void Awake()
{
if (Instance != null)
{
Destroy(this.gameObject);
return;
}
// Singleton initialization
Instance = this;
// Keep the object when changing scenes
DontDestroyOnLoad(this.gameObject);
LoadGameData();
}
public TGameDat GetGameData(string key)
{
if (gameData.TryGetValue(key, out TGameDat data))
{
return data;
}
Debug.Log($"Unable to find saved data with key {key}");
return null;
}
public void SetGameData(string key, TGameDat data)
{
// Sets a value with given key and save it to file
gameData[key] = data;
SaveGameData();
}
public void SaveGameData()
{
Serializer.SaveBinaryFile(gameData, SavePath);
}
public void LoadGameData()
{
var savedData = Serializer.LoadBinaryFile(SavePath);
if (savedData != null)
{
gameData = (Dictionary<string, TGameDat>)savedData;
}
else
{
// Creating and saving new data because we can't found
// any that already stored in path
gameData = new Dictionary<string, TGameDat>();
SaveGameData();
}
}
And then, the Serializer class
public static void SaveBinaryFile(object data, string path)
{
using (var stream = new FileStream(path, FileMode.Create))
{
var formatter = new BinaryFormatter();
formatter.Serialize(stream, data);
}
}
public static object LoadBinaryFile(string path)
{
if (!File.Exists(path))
{
// Trying to load a file that does not exist
return null;
}
using (var stream = new FileStream(path, FileMode.Open))
{
var formatter = new BinaryFormatter();
return formatter.Deserialize(stream);
}
}
And then you can use it like this
public TGameDat data;
public void TSaveVariables()
{
SaveGameManager.Instance.SetGameData(level.id, this.data);
}
public void TLoadVariables()
{
var savedData = SaveGameManager.Instance.GetGameData(level.id);
if (savedData != null)
{
this.data = savedData;
}
else
{
// We don't have any save file for this level yet
savedData = new TGameDat();
}
}
You can change level.id to whatever identifier you wanted to use.
I'm making a simple game, one of the features is challenges which are going to be opened from a file, here is how one of the challenges look:
[System.Serializable]
public class Challenge10 : ChallegeInterface {
public bool isCompleted = false;
public string description = "test";
public int curCoins;
public override void giveReward (){
GameDataSingleton.gameDataInstance.game_data.addCoinsFromReward (7);
}
//Method to check if everything is completed
public override bool isComplete (){
if (!isCompleted) {
curCoins= GameDataSingleton.gameDataInstance.game_data.getCoinsThisGame ();
if (curCoins >= 1) {
isCompleted = true;
giveReward ();
return true;
}
}
return false;
}
}
The problem is that after I deserielize the file the string value(description) is null. Here is the code where the program is opening the challenges.
public void openChallenges(){
challenges = new ChallegeInterface[game_data.challenges.Length];
for (int i = 0; i < game_data.challenges.Length; i++) {
int curChallenge = game_data.challenges[i];
ChallegeInterface challenge = HddManager.HddManagerInstance.load<ChallegeInterface> ("challenges/challenge"+curChallenge);
Debug.Log (challenge.description);
challenges[i] = challenge;
}
}
Everything else seems fine, except the description. Am i missing something?
Edit:
This is how the program is serializing the object:
public void save<T>(T data, string fileName) where T : class{
if (fileName == "")
Debug.Log ("Empty file path");
FileStream file = null;
try{
if(fileName.IndexOf("/") > 0){
string[] strDirName = fileName.Split(new char[] {'/'});
string dirName = strDirName[0];
if(!Directory.Exists(Path.Combine(Application.persistentDataPath, dirName))){
Directory.CreateDirectory(Path.Combine(Application.persistentDataPath, dirName));
}
}
file = File.Create(Path.Combine(Application.persistentDataPath, fileName));
binFormatter.Serialize(file, data);
Debug.Log ("File saved succesfully" + fileName);
}catch(IOException e){
Debug.Log(e.ToString());
}finally{
if(file != null)
file.Close();
}
}
This is how the object is deserialized:
public T load<T> (string fileName) where T : class{ // T => object type
if (fileName == null) {
Debug.Log ("Empty path to file");
return null;
} else {
FileStream file = null;
try {
//Open the file;
file = File.Open (constructFilePath(fileName), FileMode.Open);
//To be removed
Debug.Log ("File loaded succesfully");
// Deserialize the opened file, cast it to T and return it
return binFormatter.Deserialize (file) as T;
} catch (IOException e) {
//To be removed
Debug.Log (e.ToString ());
// Saves the current object in case the file doesn't exist
// Use Activator to create instance of the object,
save (Activator.CreateInstance<T> (), fileName);
// calls the function again
return load<T> (fileName);
} finally {
//Close the file
if (file != null)
file.Close ();
}
}
}
By inspecting the following lines in the openChallenges() method:
ChallegeInterface challenge = HddManager.HddManagerInstance.load<ChallegeInterface> ("challenges/challenge"+curChallenge);
Debug.Log (challenge.description);
I assume ChallegeInterface is actually a class and not an interface since interfaces can not contain fields and you are accessing challenge.description when challenge is ChallegeInterface which means ChallengeInterface is a class.
In this case you are actually accessing the base class' (ChallegeInterface) field instead of the correct one (Challenge10). and that field is empty.
Important: keep clear and correct coding conventions, never name a class Interface, it's better to avoid naming types with programming terminology instead of indicative naming related to their usage.
P.S.: I've checked the serialization myself and inspected Challenge10's description and it works fine.
I get an object of a class with some properties by calling its own static function for an instance. If there is a XML file the object tries to load it and add its values to the instance itself. Then it will save the XML again in case there are missing options in the XML file.
I created a small console app:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
using System.IO;
using System.Reflection;
using System.Xml.Serialization;
using System.Xml;
namespace Test
{
public class Program
{
static void Main(string[] args)
{
TaskServerSettings s = TaskServerSettings.LoadNew();
}
}
public class TaskServerSettings : IEqualityComparer
{
#region SETTINGS PROPERTIES
public bool Enabled { get; set; }
public int CheckInterval { get; set; }
#endregion
#region CONSTRUCTORS AND METHODS
public TaskServerSettings()
{
this.init();
}
public TaskServerSettings(string settingsFile)
{
this.init();
if (settingsFile != null)
{
if (File.Exists(settingsFile))
{
this.Load(settingsFile);
}
this.Save(settingsFile);
}
}
private void init()
{
this.Enabled = true;
this.CheckInterval = 5000;
}
public void Absorb(TaskServerSettings newSettings)
{
this.Enabled = newSettings.Enabled;
this.CheckInterval = newSettings.CheckInterval;
}
public static TaskServerSettings LoadNew(string settingsFile = null)
{
if (settingsFile == null)
{
settingsFile = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location.TrimEnd('\\')) + #"\TaskServerSettings.xml";
}
return new TaskServerSettings(settingsFile);
}
public bool Load(string settingsFile = null)
{
if (settingsFile == null)
{
settingsFile = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location.TrimEnd('\\')) + #"\TaskServerSettings.xml";
}
if (!File.Exists(settingsFile))
{
throw new FileNotFoundException("Could not find \"" + settingsFile + "\" to load settings.");
}
bool result = false;
using (FileStream fs = new FileStream(settingsFile, FileMode.Open))
{
XmlSerializer xs = new XmlSerializer(this.GetType());
if (!xs.CanDeserialize(XmlReader.Create(fs)))
{
throw new XmlException("\"" + settingsFile + "\" does not have a valid TaskServerSettings XML structure.");
}
//try
//{ // +- InvalidOperationException - Error in XML document (0,0).
// v The root element is missing.
this.Absorb(xs.Deserialize(fs) as TaskServerSettings);
result = true;
//}
//catch { }
}
return result;
}
public bool Save(string settingsFile = null)
{
if (settingsFile == null)
{
settingsFile = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location.TrimEnd('\\')) + #"\TaskServerSettings.xml";
}
bool result = false;
using (FileStream fs = new FileStream(settingsFile, FileMode.Create))
{
XmlSerializer xs = new XmlSerializer(this.GetType());
try
{
xs.Serialize(fs, this);
result = true;
}
catch { }
}
return result;
}
#endregion
public bool Equals(TaskServerSettings settingsToCompare)
{
if (this.Enabled != settingsToCompare.Enabled ||
this.CheckInterval != settingsToCompare.CheckInterval)
{
return false;
}
return true;
}
bool IEqualityComparer.Equals(object x, object y)
{
return x.Equals(y);
}
int IEqualityComparer.GetHashCode(object obj)
{
throw new NotSupportedException();
}
}
}
Writing the object with its default property values in the first run works pretty good.
The XML file looks like this then:
<?xml version="1.0"?>
<TaskServerSettings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Enabled>true</Enabled>
<CheckInterval>5000</CheckInterval>
</TaskServerSettings>
However, deserializing the same file on the second run causes the error when it tries to load the file on
xs.Deserialize(fs) as TaskServerSettings.
InvalidOperationException - Error in XML document (0,0).
The root element is missing.
I already tried to avoid the static method and tried new as well as I already tried to remove the IEqualityComparer parent + the last three methods. Without success.
I wonder, whats the cause of this error?
When you execute this statement:
if (!xs.CanDeserialize(XmlReader.Create(fs)))
it starts reading the stream. So when you call Deserialize later, the stream is not at the start, so the deserialization fails. You need to rewind the stream by setting fs.Position = 0
I am evaluating Winnovative's PdfToText library and have run into something that concerns me.
Everything runs fine and I am able to extract the text content from a small 20k or less pdf immediately if I am running a console application. However, if I call the same code from the NUnit gui running it takes 15-25 seconds (I've verified it's PdfToText by putting a breakpoint on the line that extracts the text and hitting F10 to see how long it takes to advance to the next line).
This concerns me because I'm not sure where to lay blame since I don't know the cause. Is there a problem with NUnit or PdfToText? All I want to do is extract the text from a pdf, but 20 seconds is completely unreasonable if I'm going to see this behavior under certain conditions. If it's just when running NUnit, that's acceptable, but otherwise I'll have to look elsewhere.
It's easier to demonstrate the problem using a complete VS Solution (2010), so here's the link to make it easier to setup and run (no need to download NUnit or PdfToText or even a sample pdf):
http://dl.dropbox.com/u/273037/PdfToTextProblem.zip (You may have to change the reference to PdfToText to use the x86 dll if you're running on a 32-bit machine).
Just hit F5 and the NUnit Gui runner will load.
I'm not tied to this library, if you have suggestions, I've tried iTextSharp (way too expensive for 2 lines of code), and looked at Aspose (I didn't try it, but the SaaS license is $11k). But they either lack the required functionality or are way too expensive.
(comment turned into answer)
How complex are your PDFs? The 4.1.6 version of iText allows for a closed sourced solution. Although 4.1.6 doesn't directly have a text extractor it isn't too terribly hard to write one using the PdfReader and GetPageContent().
Below is the code I used to extract the text from the PDF using iTextSharp v4.1.6. If it seems overly verbose, it's related to how I'm using it and the flexibility required.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using iTextSharp.text.pdf;
namespace ClassLibrary1
{
public class PdfToken
{
private PdfToken(int type, string value)
{
Type = type;
Value = value;
}
public static PdfToken Create(PRTokeniser tokenizer)
{
return new PdfToken(tokenizer.TokenType, tokenizer.StringValue);
}
public int Type { get; private set; }
public string Value { get; private set; }
public bool IsOperand
{
get
{
return Type == PRTokeniser.TK_OTHER;
}
}
}
public class PdfOperation
{
public PdfOperation(PdfToken operationToken, IEnumerable<PdfToken> arguments)
{
Name = operationToken.Value;
Arguments = arguments;
}
public string Name { get; private set; }
public IEnumerable<PdfToken> Arguments { get; private set; }
}
public interface IPdfParsingStrategy
{
void Execute(PdfOperation op);
}
public class PlainTextParsingStrategy : IPdfParsingStrategy
{
StringBuilder text = new StringBuilder();
public PlainTextParsingStrategy()
{
}
public String GetText()
{
return text.ToString();
}
#region IPdfParsingStrategy Members
public void Execute(PdfOperation op)
{
// see Adobe PDF specs for additional operations
switch (op.Name)
{
case "TJ":
PrintText(op);
break;
case "Tm":
SetMatrix(op);
break;
case "Tf":
SetFont(op);
break;
case "S":
PrintSection(op);
break;
case "G":
case "g":
case "rg":
SetColor(op);
break;
}
}
#endregion
bool newSection = false;
private void PrintSection(PdfOperation op)
{
text.AppendLine("------------------------------------------------------------");
newSection = true;
}
private void PrintNewline(PdfOperation op)
{
text.AppendLine();
}
private void PrintText(PdfOperation op)
{
if (newSection)
{
newSection = false;
StringBuilder header = new StringBuilder();
PrintText(op, header);
}
PrintText(op, text);
}
private static void PrintText(PdfOperation op, StringBuilder text)
{
foreach (PdfToken t in op.Arguments)
{
switch (t.Type)
{
case PRTokeniser.TK_STRING:
text.Append(t.Value);
break;
case PRTokeniser.TK_NUMBER:
text.Append(" ");
break;
}
}
}
String lastFont = String.Empty;
String lastFontSize = String.Empty;
private void SetFont(PdfOperation op)
{
var args = op.Arguments.ToList();
string font = args[0].Value;
string size = args[1].Value;
//if (font != lastFont || size != lastFontSize)
// text.AppendLine();
lastFont = font;
lastFontSize = size;
}
String lastX = String.Empty;
String lastY = String.Empty;
private void SetMatrix(PdfOperation op)
{
var args = op.Arguments.ToList();
string x = args[4].Value;
string y = args[5].Value;
if (lastY != y)
text.AppendLine();
else if (lastX != x)
text.Append(" ");
lastX = x;
lastY = y;
}
String lastColor = String.Empty;
private void SetColor(PdfOperation op)
{
lastColor = PrintCommand(op).Replace(" ", "_");
}
private static string PrintCommand(PdfOperation op)
{
StringBuilder text = new StringBuilder();
foreach (PdfToken t in op.Arguments)
text.AppendFormat("{0} ", t.Value);
text.Append(op.Name);
return text.ToString();
}
}
}
And here's how I call it:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using iTextSharp.text.pdf;
namespace ClassLibrary1
{
public class PdfExtractor
{
public static string GetText(byte[] pdfBuffer)
{
PlainTextParsingStrategy strategy = new PlainTextParsingStrategy();
ParsePdf(pdfBuffer, strategy);
return strategy.GetText();
}
private static void ParsePdf(byte[] pdf, IPdfParsingStrategy strategy)
{
PdfReader reader = new PdfReader(pdf);
for (int i = 1; i <= reader.NumberOfPages; i++)
{
byte[] page = reader.GetPageContent(i);
if (page != null)
{
PRTokeniser tokenizer = new PRTokeniser(page);
List<PdfToken> parameters = new List<PdfToken>();
while (tokenizer.NextToken())
{
var token = PdfToken.Create(tokenizer);
if (token.IsOperand)
{
strategy.Execute(new PdfOperation(token, parameters));
parameters.Clear();
}
else
{
parameters.Add(token);
}
}
}
}
}
}
}
I am trying to store a list of objects I created in the isolated storage and be able to display them in a list by auto generating a title for them. So far the code works but once I tombstone the app and start it up all my data is saved except for the list of objects. I think my problem may be with how I initialize the list in the first place, or possibly how I am displaying the names. Any help is appreciated.
this code is in my App.xaml.cs:
public partial class App : Application
{
public List<my_type> testList = new List<my_type>();
void loadvalues()
{
IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
List<my_Type> L;
if (settings.TryGetValue<List<DrinkSesh>>("Storage", out L))
{ testList = L; }
}
void savevalues()
{
IsolatedStorageSettings settings = IsolatedStorageSettings.ApplicationSettings;
settings["Storage"] = testList;
settings.Save();
}
}
This code is on my mainPage to add the items to the list:
(Application.Current as App).testList.Add(new my_type());
and this code is to implement the titles onto the screen on a different page:
public different_class()
{
{
InitializeComponent();
for (i = 0; i < (Application.Current as App).testList.Count; i++)
{
CreateATextBlock((Application.Current as App).testList[i].Title_ToString(), i);
}
}
private void CreateATextBlock(String title,int num)
{
testblockname = new TextBlock();
testblockname.Text = (num + 1) + ". " + title;
DrList.Children.Add(testblockname);
}
}
Thank you in advance!
Here is the code I use to save and load lists of objects from isolated storage.
public class IsoStoreHelper
{
private static IsolatedStorageFile _isoStore;
public static IsolatedStorageFile IsoStore
{
get { return _isoStore ?? (_isoStore = IsolatedStorageFile.GetUserStoreForApplication()); }
}
public static void SaveList<T>(string folderName, string dataName, ObservableCollection<T> dataList) where T : class
{
if (!IsoStore.DirectoryExists(folderName))
{
IsoStore.CreateDirectory(folderName);
}
string fileStreamName = string.Format("{0}\\{1}.dat", folderName, dataName);
using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(fileStreamName, FileMode.Create, IsoStore))
{
DataContractSerializer dcs = new DataContractSerializer(typeof(ObservableCollection<T>));
dcs.WriteObject(stream, dataList);
}
}
public static ObservableCollection<T> LoadList<T>(string folderName, string dataName) where T : class
{
ObservableCollection<T> retval = new ObservableCollection<T>();
if (!IsoStore.DirectoryExists(folderName))
{
IsoStore.CreateDirectory(folderName);
}
string fileStreamName = string.Format("{0}\\{1}.dat", folderName, dataName);
using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(fileStreamName, FileMode.OpenOrCreate, IsoStore))
{
if (stream.Length > 0)
{
DataContractSerializer dcs = new DataContractSerializer(typeof(ObservableCollection<T>));
retval = dcs.ReadObject(stream) as ObservableCollection<T>;
}
}
return retval;
}
}
By simply adding your collection (List) to your IsolatedStorageSettings you are relying on the built in serializer (the DataContractSerializer) to serialize your object for persisting to disk.
Are you sure your object can be correctly serialized and deserialized?
Doing this yourself is probably the easiest way to do this.
If you do this yourself, not that:
- DataContractSerializer is slow
- DataContractJsonSerializer is faster
- Json.net is faster still
- Binary serialization is fastest.
When serializing yourself you should also save in an IsolatedStorageFile rahter than in the settings. This can help with performance and also adds flexibility which can aid debugging and testing.