I am new to opening files and using "StreamReader", when I try to open up a file it displays all of the numbers as 0 instead of what they are, and I am not sure where my mistake is.

Also I am pretty sure I did not do saving right either..

Code:
Imports System.IO

Public Class ClassAverage
    Dim fileWriter As StreamWriter ' writes data to a text file
    Dim FileName As String ' name of file to save data
    Enum GradesFiles
        Grades
    End Enum
    ' places a grade in the gradesListBox
    Private Sub submitGradeButton_Click(ByVal sender As System.Object,
       ByVal e As System.EventArgs) Handles submitGradeButton.Click

        ' if the user entered a grade
        If gradeTextBox.Text <> String.Empty Then
            ' add the grade to the end of the gradesListBox
            gradesListBox.Items.Add(gradeTextBox.Text)
            gradeTextBox.Clear() ' clear the gradeTextBox
        End If

        gradeTextBox.Focus() ' gives the focus to the gradeTextBox
    End Sub ' submitGradeButton_Click

    ' calculates the class average based on the grades in gradesListBox
    Private Sub calculateAverageButton_Click(ByVal sender As System.Object,
       ByVal e As System.EventArgs) Handles calculateAverageButton.Click

        Dim total As Integer ' sum of grades entered by user
        Dim gradeCounter As Integer ' counter for grades 
        Dim grade As Integer ' grade input by user
        Dim average As Double ' average of grades

        ' initialization phase
        total = 0 ' set total to zero before adding grades to it
        gradeCounter = 0 ' prepare to loop

        ' processing phase
        Do While gradeCounter < gradesListBox.Items.Count
            grade = gradesListBox.Items(gradeCounter) ' get next grade
            total += grade ' add grade to total
            gradeCounter += 1 ' add 1 to gradeCounter
        Loop

        ' termination phase
        If gradeCounter <> 0 Then
            average = total / gradesListBox.Items.Count ' calculate average

            ' display total and average (with two digits of precision)
            classAverageLabel.Text = "Total of the " & gradeCounter &
               " grade(s) is " & total & vbCrLf & "Class average is " &
               String.Format("{0:F}", average)
        Else
            classAverageLabel.Text = "No grades were entered"
        End If
    End Sub ' calculateAverageButton_Click

    ' clears grades from gradeListBox and results from classAverageLabel
    Private Sub clearGradesButton_Click(ByVal sender As System.Object,
       ByVal e As System.EventArgs) Handles clearGradesButton.Click

        gradesListBox.Items.Clear() ' removes all items from gradesListBox
        classAverageLabel.Text = String.Empty ' clears classAverageLabel
    End Sub ' clearGradesButton_Click

    Private Sub ExitToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles ExitToolStripMenuItem.Click
        Me.Close()
    End Sub

    Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click


        Dim result As DialogResult

        Using fileChooser As New OpenFileDialog()
            result = fileChooser.ShowDialog()
            FileName = fileChooser.FileName
        End Using

        If result <> Windows.Forms.DialogResult.Cancel Then
            submitGradeButton.Enabled = True
            gradeTextBox.Enabled = True
        End If
        DisplayGrades(GradesFiles.Grades)
    End Sub

    Sub DisplayGrades(ByVal gradesFiles As GradesFiles)
        Dim fileReader As StreamReader = Nothing

        fileReader = New StreamReader(FileName)
        Do While Not fileReader.EndOfStream
            Dim line As String = fileReader.ReadLine()
            Dim Grades As Integer

            If displayif(Grades, gradesFiles) Then
                gradesListBox.Items.Add(Grades & vbCrLf)
            End If
        Loop
    End Sub
    Function displayif(ByVal Grades As Integer,ByVal type As GradesFiles) As String

        If Grades >= 0 AndAlso type = GradesFiles.Grades Then
            Return True
        End If

        Return False

    End Function

    Private Sub SaveToolStripMenuItem_Click(sender As System.Object, e As System.EventArgs) Handles SaveToolStripMenuItem.Click
        Dim result As DialogResult
        Dim filename As String
        Using fileChooser As New SaveFileDialog()
            result = fileChooser.ShowDialog()
            filename = fileChooser.FileName
        End Using

        If result <> Windows.Forms.DialogResult.Cancel Then
            Try

                fileWriter = New StreamWriter(filename, True)
            Catch ex As IOException
                MessageBox.Show("Error Opening File", "Error",
                  MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try

        End If
    End Sub
End Class
Thanks