Writing to a text file in C#, but there is an exception unhandled error

Question

I have been making a quiz for a while now, and wanted to implement a leader board. The leader board should show the name of the user, score

I have checked to see if it is recognising the file and when I remove the score it works fine. The score works fine when I am displaying it on a label in all the other forms.

public partial class frmLeaderboard : Form {enter code here //Setup player list List players = new List();

    public frmLeaderboard()
    {
         //Setup form
         InitializeComponent();
         dgLeaderboard.ColumnCount = 3;
         dgLeaderboard.Columns[0].Name = "Player Name";
         dgLeaderboard.Columns[1].Name = "Score"; 
         dgLeaderboard.Columns[2].Name = "Level";
         SaveScores();
         GetPreviousPlayers();
    }

    private void GetPreviousPlayers()
    {
        //searches for file and loads score
        if(File.Exists("previousplayers.txt"))
        {
            LoadScores();
        }

        dgLeaderboard.Sort(dgLeaderboard.Columns[1], ListSortDirection.Descending);
    }

    private void LoadScores()
    {
        if (File.Exists("previousplayers.txt"))
        {
            //Loads the score
            var playerScores = File.ReadAllLines("previousplayers.txt");

            if (playerScores.Length > 0)
            {
                //bring in the players to the grid
                foreach (var players in playerScores)
                {
                    var splitDetails = players.Split('~');
                    dgLeaderboard.Rows.Add(splitDetails[0], Convert.ToInt32(splitDetails[0]), splitDetails[2]);
                }
            }

            else
            {
                HideGrid();
            }
        }
    }

    private void SaveScores()
    {
        FileStream fileStream = new FileStream("previousplayers.txt", FileMode.Append, FileAccess.Write);
        StreamWriter streamWriter = new StreamWriter(fileStream);

        //Seperate the username, score and level
        try
        {
            foreach(var player in players)
            {
                streamWriter.WriteLine(player.Username + "~" + player.Score + "~" + player.Level);
            }
        }
        catch(Exception)
        {
            MessageBox.Show("Error Loading the scores", "Please try again");
        }
        finally
        {
            streamWriter.Close();
            fileStream.Close();
        }

    }

    private void HideGrid()
    {
        //Sets the grid to invisible
        dgLeaderboard.Visible = false;
    }



}

In the form before I use this code

string filePath = "previousplayers.txt";
        FileStream aFile;
        StreamWriter sw;

        try
        {`enter code here`
            if (!File.Exists(filePath))
            {
                aFile = new FileStream(filePath, FileMode.Create, FileAccess.Write);
            }
            else
            {
                aFile = new FileStream(filePath, FileMode.Append, FileAccess.Write);
            }

            sw = new StreamWriter(aFile);
            sw.WriteLine(frmStart.Player.Username + "~" + frmStart.Player.Score + "~" + frmStart.Player.Level);
            sw.Close();
            aFile.Close();

        }
        catch (Exception ex)
        {
            MessageBox.Show("User's details have not been saved", "Error Occurred");
        }

It crashes with the error: Exception Unhandled, System.IndexOutOfRangeException: 'Index was outside the bounds of the array.'

at this line dgLeaderboard.Rows.Add(splitDetails[0], Convert.ToInt32(splitDetails[0]), splitDetails[2]);

Blockquote

That error happens because you presented an index to the array indexer that was too large (>=array size) or a negative number. — Robert Harvey
– Robert Harvey, Commented Feb 5, 2019 at 21:26
Also, note that you don't need to check File.Exists(filePath). FileMode.Append will create the file if it doesn't exist. + Convert.ToInt32(splitDetails[0]): splitDetails[0] is a string here, containing player.Username, since: streamWriter.WriteLine(player.Username + "~" (...). Unless you're mixing different versions of the procedure. — Jimi
– Jimi, Commented Feb 5, 2019 at 21:55

Kristoffer Lerbæk Pedersen · Accepted Answer · 2019-02-05 21:33:29Z

1

You're writing the player scores this way:

player.Username + "~" + player.Score + player.Level

So if you're reading it and splitting it on ~, you'll get an array with a length of 2, where [0] is player.Username and [1] is player.Score + player.level. You're trying to access index [2], which is out of bounds.

answered Feb 5, 2019 at 21:33

Kristoffer Lerbæk Pedersen

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5 Comments

lluvatar Over a year ago

Hmm i added that extra "~" between and same error shows

Kristoffer Lerbæk Pedersen Over a year ago

Did you remember to delete the old file after changing the format? Otherwise, even though the new lines are correctly formatted, parsing the old lines will still throw.

Kristoffer Lerbæk Pedersen Over a year ago

Also, isn't it a mistake that you're trying to write the username to both the first and the second column? I'd think it should be dgLeaderboard.Rows.Add(splitDetails[0], Convert.ToInt32(splitDetails[1]), splitDetails[2]);

lluvatar Over a year ago

that must of been a mistake typing here, because it is like that in my code

Kristoffer Lerbæk Pedersen Over a year ago

Excellent, glad to hear it!

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