How do I print data from .txt to textbox list?

Question

I can't get the data to print from my .txt to my textbox? I really don't understand why. Here is what I have

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.IO;

namespace WindowsFormsApplication1

{

    public partial class Form1 : Form

    {

        const int ROWS = 5;

        const int COLS = 5;

        double[,] iArray = new double[ROWS, COLS];

        string[] nArray = new string[5];

        double[] finalGradesArray = new double[5];

        const double TOTAL = 4;

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            PopulateArrays();

            Calculations();

            //read Names.txt file

            ReadFile(); 

        }

        private void ReadFile()

        {

            //read namesFile and show it on listbox

            StreamReader namesFile;

            int index = 0;

            namesFile = File.OpenText("Names.txt");

            while (!namesFile.EndOfStream)

            {

                //studentsNamesListBox.Items.Add(namesFile.ReadLine());

                nArray[index] = namesFile.ReadLine();

                studentsNamesListBox.Items.Add(nArray[index]);

                index++;

            }

            namesFile.Close();

        }

        private void PopulateArrays()

        {

            StreamReader scoresFile; //to read the file

            string line; //to hold a line from the file

            string[] dArray; //to hold the value from text file

            int i;

            int j;

            /*   double[,] fArray = new double [5, 5];

               double[,] total = new double[5, 5];

               //to hold the iArray 2-D

               double newArray;

              */

            //open Scores.txt file

            scoresFile = File.OpenText("Scores.txt");

            //read the lines from the file

            for (i = 0; i < iArray.GetLength(0); i++)

            {

                line = scoresFile.ReadLine(); //read a line from the file

                dArray = line.Split(','); //split "," out of the strings                

                for (j = 0; j < 5; j++)

                {

                    iArray[i, j] = double.Parse(dArray[j]);       //= double.Parse(dArray[j]); //the new 1-D array will be [0] = 1.0 [1] = 0.8 [2] = 0.9... and so on ...

                }

            }

            scoresFile.Close();

            //call calculations method so the data from iArray is calculated

            //double[] tempArray = Calculations(iArray);

        }

        private void Calculations()

        {

            int i;

            int j;

            double average = 0;

            for (j = 0; j < 5; j++) //sum up the column only

            {

                for (i = 0; i < 5; i++)

                {

                    if (i != j) //ignore student own evaluation

                    {

                        average += iArray[i, j]; //Like this!!

                        //max number is 1

                        //accumulate with values

                    }

                }

                average = (average / TOTAL); //divide by number of column excluding his own for average 

                finalGradesArray[j] = average;  //store the average in the grade array

            }

        }

        private void button1_Click(object sender, EventArgs e)

        {

            try

            {

                //when click calculate button evaluation average grade * project grade = averagegradetextlabel

                double projectGrade;

                double averageStudent;

                int index;

                projectGrade = double.Parse(projectGradeTextBox.Text);

                if (studentsNamesListBox.SelectedIndex != -1)

                {

                    index = studentsNamesListBox.SelectedIndex;

                    averageGradeStudentLabel.Text = (projectGrade * finalGradesArray[index]).ToString();

                    /*

                    for (index = 0; index < 5; index++)

                    {

                        averageStudent = projectGrade * finalGradesArray[index];

                        averageGradeStudentLabel.Text = averageStudent.ToString("p2");

                    }

                     */

                }

            }

            catch (Exception ex)

            {

                MessageBox.Show(ex.Message);

            }

        }

        private void studentsNamesListBox_SelectedIndexChanged(object sender, EventArgs e)

        {

        }

        private void button2_Click(object sender, EventArgs e)

        {

            this.Close();

        }

    }

}