Printing content in Listbox

I am trying to print the content in my listbox after the program is run (The courses that are typed in, Total hours, Quantity Points, Total GPA). It is opening up my printer options but printing a blank page every time...

Code:

---

Public Class Form1

    Dim QualityPoints As Double
    Dim CourseName, hours As String

    Private Sub btnTotalHours_Click(sender As Object, e As EventArgs) Handles btnTotalHours.Click

        txtBoxTotalHours.Text = NumericUpDown1.Value + NumericUpDown2.Value + NumericUpDown3.Value + NumericUpDown4.Value + NumericUpDown5.Value + NumericUpDown6.Value + NumericUpDown7.Value + NumericUpDown8.Value

    End Sub

    Private Sub btnTotalQualityPoints_Click(sender As Object, e As EventArgs) Handles btnTotalQualityPoints.Click

        Select Case txtBoxGrade1.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown1.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown1.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown1.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown1.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown1.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown1.Value)

        End Select

        Select Case txtBoxGrade2.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown2.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown2.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown2.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown2.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown2.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown2.Value)

        End Select

        Select Case txtBoxGrade3.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown3.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown3.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown3.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown3.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown3.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown3.Value)

        End Select

        Select Case txtBoxGrade4.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown4.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown4.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown4.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown4.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown4.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown4.Value)

        End Select

        Select Case txtBoxGrade5.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown5.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown5.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown5.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown5.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown5.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown5.Value)

        End Select

        Select Case txtBoxGrade6.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown6.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown6.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown6.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown6.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown6.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown6.Value)

        End Select

        Select Case txtBoxGrade7.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown7.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown7.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown7.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown7.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown7.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown7.Value)

        End Select

        Select Case txtBoxGrade8.Text
            Case "A"
                QualityPoints += (4 * NumericUpDown8.Value)
            Case "B"
                QualityPoints += (3 * NumericUpDown8.Value)
            Case "C"
                QualityPoints += (2 * NumericUpDown8.Value)
            Case "D"
                QualityPoints += (1 * NumericUpDown8.Value)
            Case "F"
                QualityPoints += (0 * NumericUpDown8.Value)
            Case " "
                QualityPoints += (0 * NumericUpDown8.Value)

        End Select

        txtBoxTotalQualityPoints.Text = QualityPoints

    End Sub

    Private Sub btnClear_Click(sender As Object, e As EventArgs) Handles btnClear.Click

        txtBoxCourse1.Clear()
        txtBoxCourse2.Clear()
        txtBoxCourse3.Clear()
        txtBoxCourse4.Clear()
        txtBoxCourse5.Clear()
        txtBoxCourse6.Clear()
        txtBoxCourse7.Clear()
        txtBoxCourse8.Clear()

        txtBoxGrade1.Clear()
        txtBoxGrade2.Clear()
        txtBoxGrade3.Clear()
        txtBoxGrade4.Clear()
        txtBoxGrade5.Clear()
        txtBoxGrade6.Clear()
        txtBoxGrade7.Clear()
        txtBoxGrade8.Clear()

        txtBoxTotalGPA.Clear()
        txtBoxTotalHours.Clear()
        txtBoxTotalQualityPoints.Clear()

        NumericUpDown1.Value = 0
        NumericUpDown2.Value = 0
        NumericUpDown3.Value = 0
        NumericUpDown4.Value = 0
        NumericUpDown5.Value = 0
        NumericUpDown6.Value = 0
        NumericUpDown7.Value = 0
        NumericUpDown8.Value = 0


        lstBoxResults.Items.Clear()

    End Sub

    Private Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click

        Dim semester As String
        Dim totalGPA As Double = QualityPoints / txtBoxTotalHours.Text

        semester = CStr(lstBoxResults.Text)
        txtBoxTotalGPA.Text = CStr(totalGPA)
        txtBoxTotalGPA.Text = Math.Round(totalGPA, 3)

        If radButtonFall.Checked Then

            semester = "Fall"

        ElseIf radButtonSpring.Checked Then

            semester = "Spring"

        ElseIf radButtonSummer.Checked Then

            semester = "Summer"

        End If


        lstBoxResults.Items.Add(semester & " " & "Semester : ")
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add("Total Hours : " & txtBoxTotalHours.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add("Total Qualit Points : " & txtBoxTotalQualityPoints.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add("Total " & semester & " " & "GPA : " & txtBoxTotalGPA.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add("Enrolled Courses : ")
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse1.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse2.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse3.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse4.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse5.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse6.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse7.Text)
        lstBoxResults.Items.Add(" ")
        lstBoxResults.Items.Add(txtBoxCourse8.Text)

    End Sub

    Private Sub btnQuit_Click(sender As Object, e As EventArgs) Handles btnQuit.Click

        End

    End Sub

    Private Sub PrintDocument1_PrintPage(sender As Object, e As Printing.PrintPageEventArgs) Handles PrintDocument1.PrintPage

        Dim font1 As New Font("Arial", 16, FontStyle.Regular)
        e.Graphics.DrawString(lstBoxResults.Text, font1, Brushes.Black, 100, 100)

    End Sub

    Private Sub btnPrint_Click(sender As Object, e As EventArgs) Handles btnPrint.Click

        PrintDialog1.ShowDialog()
        PrintDocument1.Print()

    End Sub
End Class

---

Any assistance is appreciated!

The Text property of a ListBox returns the text displayed in the ListBox for the SelectedItem. I'm guessing that you have not selected any item so Text is Nothing.

You really shouldn't be using a ListBox for that anyway. You should be using a TextBox. You can create one String and print it as well as assign it to the Text of the TextBox. If you really must use a ListBox then you'll need to loop through the items and print each one. To get the text of an item you can call GetItemText on the ListBox.