' Gpa2 Example

' Enter grade and credits sequentially.  Output GPA.

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents btnEnter As System.Windows.Forms.Button
    Friend WithEvents txtGrade As System.Windows.Forms.TextBox
    Friend WithEvents txtGpa As System.Windows.Forms.TextBox
    Friend WithEvents Label3 As System.Windows.Forms.Label
    Friend WithEvents GPA As System.Windows.Forms.Label
    Friend WithEvents Compute As System.Windows.Forms.Button
    Friend WithEvents btnReset As System.Windows.Forms.Button
    Friend WithEvents txtCredits As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.txtGrade = New System.Windows.Forms.TextBox
        Me.Label1 = New System.Windows.Forms.Label
        Me.btnEnter = New System.Windows.Forms.Button
        Me.txtGpa = New System.Windows.Forms.TextBox
        Me.txtCredits = New System.Windows.Forms.TextBox
        Me.Label3 = New System.Windows.Forms.Label
        Me.GPA = New System.Windows.Forms.Label
        Me.Compute = New System.Windows.Forms.Button
        Me.btnReset = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'txtGrade
        '
        Me.txtGrade.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txtGrade.Location = New System.Drawing.Point(120, 16)
        Me.txtGrade.Name = "txtGrade"
        Me.txtGrade.Size = New System.Drawing.Size(72, 29)
        Me.txtGrade.TabIndex = 0
        Me.txtGrade.Text = ""
        '
        'Label1
        '
        Me.Label1.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label1.Location = New System.Drawing.Point(40, 16)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(72, 24)
        Me.Label1.TabIndex = 1
        Me.Label1.Text = "Grade"
        '
        'btnEnter
        '
        Me.btnEnter.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.btnEnter.Location = New System.Drawing.Point(208, 16)
        Me.btnEnter.Name = "btnEnter"
        Me.btnEnter.Size = New System.Drawing.Size(248, 32)
        Me.btnEnter.TabIndex = 4
        Me.btnEnter.Text = "Enter Grade and Credits"
        '
        'txtGpa
        '
        Me.txtGpa.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txtGpa.Location = New System.Drawing.Point(120, 96)
        Me.txtGpa.Name = "txtGpa"
        Me.txtGpa.ReadOnly = True
        Me.txtGpa.Size = New System.Drawing.Size(72, 29)
        Me.txtGpa.TabIndex = 2
        Me.txtGpa.Text = "0"
        '
        'txtCredits
        '
        Me.txtCredits.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.txtCredits.Location = New System.Drawing.Point(120, 56)
        Me.txtCredits.Name = "txtCredits"
        Me.txtCredits.Size = New System.Drawing.Size(72, 29)
        Me.txtCredits.TabIndex = 5
        Me.txtCredits.Text = ""
        '
        'Label3
        '
        Me.Label3.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label3.Location = New System.Drawing.Point(32, 64)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(72, 24)
        Me.Label3.TabIndex = 6
        Me.Label3.Text = "Credits"
        '
        'GPA
        '
        Me.GPA.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.GPA.Location = New System.Drawing.Point(56, 104)
        Me.GPA.Name = "GPA"
        Me.GPA.Size = New System.Drawing.Size(56, 24)
        Me.GPA.TabIndex = 7
        Me.GPA.Text = "GPA"
        '
        'Compute
        '
        Me.Compute.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Compute.Location = New System.Drawing.Point(208, 56)
        Me.Compute.Name = "Compute"
        Me.Compute.Size = New System.Drawing.Size(248, 32)
        Me.Compute.TabIndex = 8
        Me.Compute.Text = "Compute GPA"
        '
        'btnReset
        '
        Me.btnReset.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.btnReset.Location = New System.Drawing.Point(208, 96)
        Me.btnReset.Name = "btnReset"
        Me.btnReset.Size = New System.Drawing.Size(248, 32)
        Me.btnReset.TabIndex = 9
        Me.btnReset.Text = "Reset"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(480, 150)
        Me.Controls.Add(Me.btnReset)
        Me.Controls.Add(Me.Compute)
        Me.Controls.Add(Me.GPA)
        Me.Controls.Add(Me.Label3)
        Me.Controls.Add(Me.txtCredits)
        Me.Controls.Add(Me.btnEnter)
        Me.Controls.Add(Me.txtGpa)
        Me.Controls.Add(Me.Label1)
        Me.Controls.Add(Me.txtGrade)
        Me.Name = "Form1"
        Me.Text = "Over90 Example"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private totalGradePoints, totalCredits As Double

    Private Sub Form1_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load

        btnReset.PerformClick()
    End Sub

    Private Sub btnEnter_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles btnEnter.Click

        Dim grade As String
        Dim credits As Integer

        grade = txtGrade.Text
        credits = txtCredits.Text
        Select Case grade
            Case "A" : totalGradePoints += 4 * credits
            Case "B" : totalGradePoints += 3 * credits
            Case "C" : totalGradePoints += 2 * credits
            Case "D" : totalGradePoints += 1 * credits
        End Select
        totalCredits += credits
        txtGrade.Clear()
        txtCredits.Clear()
        txtGrade.Focus()
    End Sub

    Private Sub Compute_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Compute.Click

        Dim gpa As Double
        If totalCredits > 0 Then
            gpa = totalGradePoints / totalCredits
            txtGpa.Text = gpa.ToString("0.00")
        Else
            txtGpa.Text = "NaN"    ' NaN means not a number.
        End If
    End Sub


    Private Sub btnReset_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles btnReset.Click

        totalCredits = 0
        totalGradePoints = 0
        txtGrade.Clear()
        txtCredits.Clear()
        txtGpa.Clear()
        txtGrade.Focus()
    End Sub
End Class