Cart Total All Items VB

Question

User2090826535 posted

I have a simple project that gets a product and sends  the Quantity to a cart where I can display the items total.

My issue is how can I total the items for a grand total.

This is what I'm using to template a project , http://www.beansoftware.com/ASP.NET-Tutorials/Developing-Shopping-Cart.aspx

Below I modified the cartItem.vb class to give me item qty total. Just need to total all the items and send to like a label.

Public Class CartItem
    Public Product As Product
    Public Quantity As Integer


    Public Function Display() As String

        Return Product.Name + ", Qty " + Quantity.ToString() _
            + " at " + FormatCurrency(Product.UnitPrice) + " each,  Current Item Total " + FormatCurrency(Quantity * Product.UnitPrice)
    End Function

 

Answer 1

User281315223 posted

Since you know that you can get the total of a single item by multiplying the Quantity and the Product.UnitPrice properties, you would just need to do this for every item within your Cart (which I am assuming is a collection of CartItem objects :

' Retrieve the total for all of the items in your Shopping Cart'
Dim total = YourShoppingCartItems.Sum(Function(i) i.Quantity * Product.UnitPrice)

Without knowing a bit more about your ShoppingCart class itself, this is just a guess. But basically you can use the available Sum() method through LINQ to calculate the total for each item in your collection (e.g. YourShoppingCartItems or Cart.Items, however you have it defined) and then sum those.

Answer 2

User2090826535 posted

Rion  - I'm having an issue placing that logic in the code. This is as close as I can get.

This is the cartitem.vb class.

Public Function Display() As String

        Return Product.Name + ", Qty " + Quantity.ToString() _
            + " at " + FormatCurrency(Product.UnitPrice) + " each,  Current Item Total " + FormatCurrency(Quantity * Product.UnitPrice)
    End Function

    Public Function Tsum() As String
        Dim CartItem As CartItem
        Dim CartEntry As DictionaryEntry
        Dim t As String
        For Each t In CartItem.Product
            Dim total = CartItems.Sum(Function(i) i.Quantity * Product.UnitPrice)
            Return total
        Next

    End Function

Answer 3

User281315223 posted

What does your "Cart" object look like?

I would imagine that it contains a collection of items (e.g. CartItems) that you would use to get a total for. If that is the case, you could simply define a function on it to return the total :

' Define this on your actual Cart '
Public Function GetTotal() As Decimal
    Dim total = CartItems.Sum(Function(i) i.Quantity * Product.UnitPrice)
    Return total
End Function

Answer 4

User2090826535 posted

Here is the cart object with the additional code. I missing something.

Imports Microsoft.VisualBasic

Public Class CartItem
    Public Product As Product
    Public Quantity As Integer

    Public Function Display() As String

        Return Product.Name + ", Qty " + Quantity.ToString() _
            + " at " + FormatCurrency(Product.UnitPrice) + " each,  Current Item Total " + FormatCurrency(Quantity * Product.UnitPrice)
    End Function

    ' Define this on your actual Cart '
    Public Function GetTotal() As Decimal
        Dim total = CartItem.Sum(Function(i) i.Quantity * Product.UnitPrice)
        Return total
    End Function

End Class

Here it the aspx page to display it. This works just need the total.


 Private Sub DisplayCart()
        lstCart.Items.Clear()
        Dim CartItem As CartItem
        Dim CartEntry As DictionaryEntry
        For Each CartEntry In Cart
            CartItem = CType(CartEntry.Value, CartItem)
            lstCart.Items.Add(CartItem.Display)

        Next

    End Sub

Answer 5

User281315223 posted

So it looks like you are storing all of your individual cart items within a collection (Cart) if that is the case, you can use that to grab your total :

Private Sub GetTotal() As Decimal
     Return Cart.Sum(Function(c) c.Quantity * c.Product.UnitPrice)
End Sub

Answer 6

User2090826535 posted

I have the GetTotal function in my Class called Cartitem.vb it wants cart to be declared I have tried Decimal, Integer and String none work.

I believe this is what your indicating.

Imports Microsoft.VisualBasic


Public Class CartItem
    Public Product As Product
    Public Quantity As Integer
    Public Cart As Decimal

    Public Function Display() As String

        Return Product.Name + ", Qty " + Quantity.ToString() _
            + " at " + FormatCurrency(Product.UnitPrice) + " each,  Current Item Total " + FormatCurrency(Quantity * Product.UnitPrice)
    End Function


    Public Function GetTotal() As Decimal
        Return Cart.Sum(Function(c) c.Quantity * c.Product.UnitPrice)
    End Function

Answer 7

User2090826535 posted

With this it say's sum is not a member of Decimal.

Public Class CartItem
    Public Product As Product
    Public Quantity As Integer
    Public Cart As Decimal

    Public Function Display() As String

        Return Product.Name + ", Qty " + Quantity.ToString() _
            + " at " + FormatCurrency(Product.UnitPrice) + " each,  Current Item Total " + FormatCurrency(Quantity * Product.UnitPrice)
    End Function


    Public Function GetTotal() As Decimal
        Return Cart.Sum(Function(c) c.Quantity * c.Product.UnitPrice)
    End Function




End Class

Answer 8

User281315223 posted

Try Double :

Public Function GetTotal() As Double
        Return Cart.Sum(Function(c) c.Quantity * c.Product.UnitPrice)
End Function

Answer 9

User2090826535 posted

No go on Double.

Thanks

Answer 10

User281315223 posted

I suppose you could try explicitly converting the value :

Public Function GetTotal() As Decimal
        Return Convert.ToDecimal(Cart.Sum(Function(c) c.Quantity * c.Product.UnitPrice))
End Function