Automatically Get Data from DataBase in ObservableCollection : WPF MVVM Caliburn Micro

Question

I am working on Data Management project which was designed in WinForms and not I am redesigning it in WPF(MVVM) I am using caliburn micro obviously to reduce development time and flexibility, I came across a huddle where I want to refresh the Data Grid as soon as I save the data into Database. Here is explanation of what i want to achieve.

1) GameModel : Contains 5 properties same as Database(GameID,GameName,GameCategory,GameCompany,GamePrice)

private string _gameID;
    private string _gameName;
    private string _gameComp;
    private string _gameCat;
    private int _gamePrice;

    public int GamePrice
    {
        get { return _gamePrice; }
        set
        {
            _gamePrice = value;
            NotifyOfPropertyChange(() => GamePrice);
        }
    }
    public string GameCat
    {
        get { return _gameCat; }
        set { _gameCat = value;
            NotifyOfPropertyChange(() => GameCat);
        }
    }
    public string GameComp
    {
        get { return _gameComp; }
        set { _gameComp = value;
            NotifyOfPropertyChange(() => GameComp);
        }
    }
    public string GameName
    {
        get { return _gameName; }
        set { _gameName = value;
            NotifyOfPropertyChange(() => GameName);
        }
    }
    public string GameID
    {
        get { return _gameID; }
        set { _gameID = value;
            NotifyOfPropertyChange(() => GameID);
        }
    }

2) GameData (DataAccessLayer): Contains method to Add data into database for sake of simplicity I am using DataTable for this example to get the answer.

DataTable dt;
    public GameData()
    {
         dt = new DataTable("gameMaster");
        DataColumn col1 = new DataColumn("Srno", typeof(int));
        col1.AutoIncrement = true;
        col1.AutoIncrementSeed = 1;
        dt.Columns.Add(col1);
        dt.Columns.Add("GameID", typeof(string));
        dt.Columns.Add("GameName", typeof(string));
        dt.Columns.Add("GameComp", typeof(string));
        dt.Columns.Add("GameCat", typeof(string));
        dt.Columns.Add("GamePrice", typeof(int));
    }
    public bool AddNewGame(GameModel gm)
    {
        try
        {
            dt.Rows.Add(null, gm.GameID, gm.GameName, gm.GameComp, gm.GameCat, gm.GamePrice);
            return true;
        }
        catch (Exception e)
        {
            MessageBox.Show(e.ToString());
            return false;
        }
    }

    public List GetAllGames()
    {
        var gameList = new List();
        foreach(DataRow row in dt.Rows)
        {
            var game = new GameModel
            {
                GameID = row[1].ToString(),
                GameName = row[2].ToString(),
                GameComp= row[3].ToString(),
                GameCat= row[4].ToString(),
                GamePrice= (int)row[5],
            };
            gameList.Add(game);
        }
        return gameList;
    }

3) GameViewModel : Contains ObservableCollection which gets data from GameData : GetAllGames method.

public GameData _gameData;
    public GameModel _gameModel;
    public GameViewModel()
    {
        GameCat.Add("Action");
        GameCat.Add("Arcade");
        GameCat.Add("Racing");
        GameCat.Add("Puzzle");
        GameCat.Add("Other");
        GameComp.Add("EA");
        GameComp.Add("EA Sports");
        GameComp.Add("Ubisoft");
        _gameData = new GameData();
        RefreshGames();
    }
    private ObservableCollection _allGames;
    public ObservableCollection AllGames
    {
        get { return _allGames; }
        set
        {
            _allGames = value;
            NotifyOfPropertyChange(() => AllGames);
        }
    }

    public void AddNewGame(string gameID, string gameName, string gameCat, string gameComp, int gamePrice)
    {
        _gameModel = new GameModel
        {
            GameID = gameID,
            GameName = gameName,
            GameCat = gameCat,
            GameComp = gameComp,
            GamePrice = gamePrice
        };

        if (_gameData.AddNewGame(_gameModel))
        {
            RefreshGames();
            MessageBox.Show("Game Added succesfully !");
        }
    }
    public void RefreshGames()
    {
        var obj = new ObservableCollection(_gameData.GetAllGames());
        AllGames = obj;
    }

Here I've to use another method in order to Refresh the ObservableCollection or you can say to populate data from DB. I want that whenever I add any data this should be automatically done. How to make it aware that any insertion was done.

And for reference I am sharing the last portion of the code View as follow :

Binding Works Fine, Data is showing fine but I want it to be done Automatically, Please let me know how can i do this without calling the RefreshGames method.

Thank you in Advance and sorry if this question is long but for sake of understanding i had to put everything.

if any one wants to share their review on Code please share it.

Andy · Accepted Answer

An observablecollection notifies collection changed when you add or remove entries from it. You seem to be talking about

public ObservableCollection AllGames

Which is in the same viewmodel as AddNewGame. If you just do

AllGames.Add(_gameModel);

In AddNewGame.
Then your ListView will show the new game as a new row.

An assumption here is that the one user is adding and viewing the games.
In a situation where other users could insert a new game and you want to see that appear then the simple solution is to poll the database every few minutes.
That isn't practical if you have a LOT of users and a lot of data changing but this doesn't look like that sort of a requirement.

Automatically Get Data from DataBase in ObservableCollection : WPF MVVM Caliburn Micro

Answers (1)

Related Questions