C＃SQLite Windows CE“内存不足异常”。

Question

So I keep having a problem where I'm getting an error stating I'm out of memory. I have a main thread and a worker thread that uses a file called SqlLiteAssetCommands.cs which contains some commands such as the following.

    Database newConnection;
    /// <summary>
    /// Open connection return the SQLlight command
    /// </summary>
    /// <returns></returns>
    private SQLiteCommand openConnection()
    {
        newConnection = new Database();
        SQLiteCommand command = new SQLiteCommand();
        try
        {
            newConnection.OpenConnection();
            command = newConnection.Connection.CreateCommand();
        }
        catch (Exception e)
        {
            log.Error("Could not open connection.", e);
        }
        return command;
    }

    /// <summary>
    /// Close connection to the local database.
    /// </summary>
    private void closeConnection()
    {
        try
        {
            newConnection.CloseConnection();
        }
        catch (Exception e)
        {
            log.Error("Could not close the connection.", e);
        }
    }

    /// <summary>
    /// Creates a transaction.
    /// </summary>
    /// <returns>Returns the new transaction that is created.</returns>
    private SQLiteTransaction getTransaction()
    {
        SQLiteTransaction sqlTransaction = null;
        try
        {
            sqlTransaction = newConnection.Connection.BeginTransaction();
        }
        catch (Exception e)
        {
            log.Error("Could not get sqlTransaction.", e);
        }
        return sqlTransaction;
    }

    #region Asset Database commands

    /// <summary>
    /// Delete all rows from sqlite database.
    /// </summary>
    /// <returns>Returns "Completed" if successful.</returns>
    public String deleteAllRows()
    {
        SQLiteCommand command = openConnection();
        String status = null;
        using (SQLiteTransaction sqlTransaction = getTransaction())
        {
            try
            {
                command.CommandText = @"DELETE FROM Asset";
                using (SQLiteDataReader reader = command.ExecuteReader())
                {
                    if (reader.HasRows)
                    {
                        reader.Read();
                    }
                    reader.Close();
                }
                status = "Completed";
                sqlTransaction.Commit();
            }
            catch (Exception e)
            {
                log.Error("Could not delete all assets.", e);
            }
        }
        closeConnection();
        return status;
    }

So my open connection is called from a different file called Database.cs and the error is caught on the open function stating I'm out of memory. I'm not sure what I need to do to keep this from happening as I cannot force the error to occur. This time happened when I was trying to force an error to show so I could screen-shoot it and finally got tired of trying and waited without doing anything. Then it just happened due to my worker thread.

    public SQLiteConnection Connection = new SQLiteConnection();
    // Define a static logger variable so that it references the name of your class
    private static readonly ILog log = LogManager.GetLogger(typeof(Database));

    // Try to open a connection to the sqlLight database.
    public void OpenConnection()
    {
        try
        {
            Connection = new SQLiteConnection("Data Source=" + Utilities.Global.SqlLiteDB);
            Connection.Open();
        }
        catch (Exception eErr)
        {
            log.Error("Error connecting to database.", eErr);
            MessageBox.Show("Error connecting to database.", "Error", MessageBoxButtons.OK, MessageBoxIcon.None, MessageBoxDefaultButton.Button1);
        }
    }
    // Close the database connection.
    public void CloseConnection()
    {
        Connection.Close();
    }
}

Anything I can do to fix this or improve my code would be helpful.

Here is the code for my worker thread since this may be the root cause of the problem.

class AssettoServerThread
{
    // Define a static logger variable so that it references the name of your class
    private static readonly ILog log = LogManager.GetLogger(typeof(AssettoServerThread));

    WebServicesSyncAsset syncAsset = new WebServicesSyncAsset();
    SqlLightAssetCommands assetToSql = new SqlLightAssetCommands();


    /////////////////////// Variables //////////
    private volatile bool _shouldStop = false;

    // SINGLETON ///////////////////////////////
    private static AssettoServerThread instance = null;

    public static AssettoServerThread GetInstance()
    {
        if (instance == null)
            instance = new AssettoServerThread();

        return instance;
    }
    // /////////////////////////////////////////

    // this variable will hold the condition of ServicesAvailable set by the worker thread
    private bool areServicesAvailable = false;

    private bool AreServicesAvailable
    {
        get { return areServicesAvailable; }
        set { areServicesAvailable = value; }
    }

    // This method will be called when the thread is stopped. 
    public void RequestStop()
    {
        _shouldStop = true;
    }

    // Create a worker thread and then check if the webservices are available.
    // If available then set ServicesAvailable to true and begin sending updated assets to the server.
    public void DoThreading()
    {
        // Continuous loop
        while (!_shouldStop)
        {
            try
            {
                // Creates an HttpWebRequest for the specified URL.
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppConfigSettings.serverIP);
                // Set some reasonable limits on resources used by this request
                request.KeepAlive = false;
                request.ProtocolVersion = HttpVersion.Version10;
                // Sends the HttpWebRequest and waits for a response.
                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                {
                    //request.Abort();
                    if (response.StatusCode == HttpStatusCode.OK)
                    {
                        areServicesAvailable = true;
                    }
                    // Releases the resources of the response.
                    response.Close();
                }
            }
            catch (WebException ex)
            {
                areServicesAvailable = false;
                log.Info("Website is currently not accessible. Therefore the services are not accessible.", ex);
            }
            catch (Exception ex)
            {
                areServicesAvailable = false;
                log.Info("Website is currently not accessible. Therefore the services are not accessible.", ex);
            }

            // If the webservices are available then run else sleep for 30 seconds.
            if (AreServicesAvailable)
            {
                try
                {
                    assetToSql.AddAssetsToServer();
                    Thread.Sleep(2000);
                }
                catch (Exception e)
                {
                    log.Error("Could not add asset to server.", e);
                }
            }
        }
    }
}

Answer 1

Then it just happened due to my worker thread.

Your threading code might be relevant, then.

Answer 2

What I ended up doing was instead of having two threads I made it into one worker thread and made sure it never overlapped. I also added a connection pool to my SQLlite database. I also changed the images on my project and deleted all unnecessary images to save space. I don't know what fixed it but this worked for me.