FROM LESSON 3: USING TOTALS & COUNTS

'Here we use module-level variables to keep a running total of the number of items and grand total as they
'purchase stuff at our store.

'Module-level variables are declared (DIMmed) in the form but before any events. I always put mine just before
'the Windows form generated code region.


Public Class frmCounts
    Inherits System.Windows.Forms.Form

    '---module level variables   
    Dim m_sngGrandTotal As Single = 0     'hold the running total
    Dim m_intNumItems As Short = 0       'hold the number of items bought



WINDOWS FORM GENERATED CODE IS IN HERE


 Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
        '---take item and cost & put them in textbox
        txtItem.Text = Trim(Mid(lstItems.SelectedItem, 1, 15))
        txtCost.Text = Trim(Mid(lstItems.SelectedItem, 16))
        txtCost.Text = FormatNumber(txtCost.Text, 2)
        
        '---add this cost to the running total
        m_sngGrandTotal += CSng(txtCost.Text)
        m_intNumItems += 1     'same as m_intNumItems = m_intNumItems + 1

    End Sub

    Private Sub btnCheckOut_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCheckOut.Click
        lblTotalSpent.Text = "You spent " & m_sngGrandTotal & " today. Thanks!"
        lblNumItems.Text = "You purchased " & m_intNumItems & " items."

    End Sub

  
End Class