Working with percentages

[newvbusernoob]

So i got the "read from file" code correct but im wondering how exactly i can get everything I need to be written to the file. More info in the last comment i have posted at the bottom.


Here is the visual design.

Public Class GradeCalculator

    Private Sub calculateButton_Click(sender As System.Object, e As System.EventArgs) Handles calculateButton.Click
        'declare variables and constants
        Const EXAM1WV As Double = 0.2
        Const EXAM2WV As Double = 0.3
        Const LAB2WV As Double = 0.05
        Const LAB3WV As Double = 0.1
        Const LAB4WV As Double = 0.1
        Const LAB5WV As Double = 0.1
        Const FINALWV As Double = 0.15
        Dim lab2 As Double
        Dim lab3 As Double
        Dim lab4 As Double
        Dim lab5 As Double
        Dim exam1 As Double
        Dim exam2 As Double
        Dim finalProject As Double
        Dim total As Double
        Dim totalWv As Double
        Dim endTotal As Double


        If lab2CheckBox.Checked = True Then
            lab2 = Val(lab2TextBox.Text) / 100 * LAB2WV
            total += lab2
            totalWv += LAB2WV
        End If

        If lab3CheckBox.Checked = True Then
            lab3 = Val(lab3TextBox.Text) / 100 * LAB3WV
            total += lab3
            totalWv += LAB3WV
        End If

        If lab4CheckBox.Checked = True Then
            lab4 = Val(lab4TextBox.Text) / 100 * LAB4WV
            total += lab4
            totalWv += LAB4WV
        End If

        If lab5CheckBox.Checked = True Then
            lab5 = Val(lab5TextBox.Text) / 100 * LAB5WV
            total += lab5
            totalWv += LAB5WV
        End If

        If exam1CheckBox.Checked = True Then
            exam1 = Val(exam1TextBox.Text) / 100 * EXAM1WV
            total += exam1
            totalWv += EXAM1WV
        End If

        If exam2CheckBox.Checked = True Then
            exam2 = Val(exam2TextBox.Text) / 100 * EXAM2WV
            total += exam2
            totalWv += EXAM2WV
        End If

        If finalCheckBox.Checked = True Then
            finalProject = Val(finalTextBox.Text) / 100 * FINALWV
            total += finalProject
            totalWv += FINALWV
        End If

        endTotal = total / totalWv
        percentageLabel.Text = String.Format("{0:P}", endTotal)










    End Sub
 Private fileName As String = "test3.txt"
    Private Sub writeButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles writeButton.Click

            If percentageLabel.Text = String.Empty Then
                MessageBox.Show("Please enter the Grades to write.", "Enter Grade", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)

            Else
                'create the StreamWriter object

                Dim output = New StreamWriter(fileName, True)

                'write to file the grade
            output.WriteLine("For the following graded items:" & ControlChars.NewLine)

                'close the file
                output.Close()

            'tell user that the information was written to file
                MessageBox.Show("The grades have been succesfully written to file", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Information)

                'make it possible to read
                readButton.Visible = True
                displayTextBox.Visible = True

            End If

    End Sub

    Private Sub readButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles readButton.Click
        Try

            'variable to store info read from file
            Dim line As String = ""

            'create the StreamReader object
            Dim input = New StreamReader(fileName)


            'make do while loop
            Do While (input.EndOfStream() = False)
                line &= input.ReadLine()
                line &= ControlChars.NewLine
            Loop

            'close the file that has been read
            input.Close()

            'display what is stored in line variable in the read text box
            displayTextBox.Text = line

            'if file does not exist, inform user to first write to file 
        Catch ex As Exception
            MessageBox.Show("File does not exist...please first write to file.", "File does not exist", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
        clearButton.Visible = True
    End Sub

    Private Sub clearButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles clearButton.Click
        displayTextBox.Text = String.Empty
    End Sub
End Class
End Class