Store different values from a single ComboBox and a single NumericUpDown

[Ricky1ST]

Hello all! I made some time ago a not very well organized question about my database driven application. My primary language is Spanish so I will try to be concise and clear. I have an ADD button in a MENU form, 4 TABS with each TAB having its own NUMERICUPDOWN, COMBOBOX and PRICE LABEL. When you open the COMBOBOX it fills up with different food names from a database made in MySQL. You choose one of the names in the combo box and AUTOMATICALLY the labels display it's price (Stored in the database). The problem is that if I press ADD a Sub Total label outside the TabControl keeps record of the added prices, and it works fine between tabs, but when I press ADD when selecting ANOTHER item from the SAME COMBOBOX inside one tab, the price in subtotal gets overridden by the new value (Only happens when selecting items between one combobox). How do I stop this? How to I sum the different prices coming from one combobox with only a global ADD button?

This is the code for the button ADD:

Private Sub btnAddAll_Click(sender As System.Object, e As System.EventArgs) Handles btnAddAll.Click
        Dim winesPrice As Decimal
        Dim appetizersPrice As Decimal
        Dim dishesPrice As Decimal
        Dim dessertsPrice As Decimal

        dessertsPrice = dessertsPrice + (numDesserts.Value * CDec(Val(lblPriceDesserts.Text)))
        dishesPrice = dishesPrice + (numDishes.Value * CDec(Val(lblPriceDishes.Text)))
        winesPrice = winesPrice + (numWines.Value * CDec(Val(lblPriceWines.Text)))
        appetizersPrice = appetizersPrice + (numAppetizers.Value * CDec(Val(lblPriceAppetizers.Text)))

        globalDesserts = dessertsPrice
        globalWines = winesPrice
        globalDishes = dishesPrice
        globalAppetizers = appetizersPrice

        globalSubTotal = globalDishes + globalDesserts + globalWines + globalAppetizers
        lblSubTotal.Text = globalSubTotal

    End Sub

This is the CODE for one of the comboboxes (They all share the same kind of code):

 Try
            MySQLConn.Open()
            Dim query As String
            query = "select * from database.meals where MealName = '" & cmbDesserts.Text & "'" 'Se busca la tabla de meals
            command = New MySqlCommand(query, MySQLConn)
            reader = command.ExecuteReader
            While reader.Read
                lblDesDesserts.Text = reader.GetString("Description")
                lblPriceDesserts.Text = reader.GetDecimal("Price")
                If cmbDesserts.Text = "Panna Cotta" Then
                    Me.picDesserts.Image = Image.FromFile(driveLetter & imagePath & "\Panna Cotta (Dessert).jpg")
                ElseIf cmbDesserts.Text = "Bellini Granita" Then
                    Me.picDesserts.Image = Image.FromFile(driveLetter & imagePath & "\Bellini Granita (Desserts).jpg")
                ElseIf cmbDesserts.Text = "Della Parfait" Then
                    Me.picDesserts.Image = Image.FromFile(driveLetter & imagePath & "\Parfait (Dessert).jpg")      
                End If

            End While
            MySQLConn.Close() 'Cerrar coneccion
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        Finally
            MySQLConn.Dispose()
        End Try
    End Sub

This is the final ORDER BUTTON:

Private Sub btnOrder_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOrder.Click
        Dim winesPrice As Decimal
        Dim appetizersPrice As Decimal
        Dim dishesPrice As Decimal
        Dim dessertsPrice As Decimal


        dessertsPrice = dessertsPrice + (numDishes.Value * CDec(Val(lblPriceDesserts.Text)))
        dishesPrice = dishesPrice + (numDishes.Value * CDec(Val(lblPriceDishes.Text)))
        winesPrice = winesPrice + (numWines.Value * CDec(Val(lblPriceWines.Text)))
        appetizersPrice = appetizersPrice + (numAppetizers.Value * CDec(Val(lblPriceAppetizers.Text)))

        globalDesserts = dessertsPrice
        globalWines = winesPrice
        globalDishes = dishesPrice
        globalAppetizers = appetizersPrice

        globalSubTotal = globalDishes + globalDesserts + globalWines + globalAppetizers
        lblSubTotal.Text = globalSubTotal

        GlobalVariables.globalPrice = globalSubTotal

        If GlobalVariables.globalPrice = 0 Then
            MsgBox("You haven't chosen any dishes!", MsgBoxStyle.Critical)
        Else
            Me.Hide()
            frmPayment.Show() 'Ir a ventana de pago
        End If
    End Sub

This is the FORM LOAD CODES and Global Variables that pass values to the next form:

Imports MySql.Data.MySqlClient 'Añade como referencia MySQL.Data.dll
Imports System.IO

Public Class frmMenu
    Public Class GlobalVariables
        Public Shared globalPrice As Decimal 'Variable de acceso global
    End Class
    Dim reader As MySqlDataReader
    Dim MySQLConn As MySqlConnection
    Dim command As MySqlCommand

    Dim drivePath As DriveInfo 'Direccion actual del proyecto
    Dim imagePath As String = "\Universidad\Systems Development & Implementation\Asignaciones\Proyecto Final\Iconos y Fotos"
    Dim driveLetter As String

    Dim globalSubTotal As Decimal
    Dim globalDishes As Decimal 'Variables de acceso local
    Dim globalWines As Decimal
    Dim globalAppetizers As Decimal
    Dim globalDesserts As Decimal

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

        For Each Me.drivePath In DriveInfo.GetDrives 'Busca la letra del "drive" del USB/CDROM y lo pasa a una variable
            If drivePath.IsReady Then
                If drivePath.DriveType = IO.DriveType.Removable Then
                    driveLetter = drivePath.Name
                ElseIf drivePath.DriveType = IO.DriveType.CDRom Then
                    driveLetter = drivePath.Name
                End If
            End If
        Next

[jmcilhinney]

When you click the Add button you can test which TabPage is selected and then you know to add to the subtotal for that page. You could use a Dictionary or an array or just discrete variables to keep the subtotals separate.

[Ricky1ST]

I haven't tried Arrays nor know how to use Dictionary yet. Can you tell me an example on how to do it? I am also overusing variables and I know I am being redundant in my code, but I will take the step by step approach and make the application smoother. I tried to make a variable every time the user clicks on a name from the combobox, then add an IF statement in the ADD button that would ask " If Not variable = 0 then" but it didn't work. I am trying to reduce code as much as possible, because before, I had 4 ADD buttons in each TabPage and still had the same problem).

[jmcilhinney]

I haven't tried Arrays nor know how to use Dictionary yet. Can you tell me an example on how to do it? I am also overusing variables and I know I am being redundant in my code, but I will take the step by step approach and make the application smoother. I tried to make a variable every time the user clicks on a name from the combobox, then add an IF statement in the ADD button that would ask " If Not variable = 0 then" but it didn't work. I am trying to reduce code as much as possible, because before, I had 4 ADD buttons in each TabPage and still had the same problem).

You would create an array with the same number of elements as there are TabPages in the TabControl. You can then use the SelectedIndex of the TabControl to access the corresponding element of the array, to add something to it or whatever.

If you don't know how to use arrays then I suggest that you follow the Tutorial link in my signature below.