Discussion 140 Comments

1. Shafiur Rahman says:

   May 23, 2009 at 2:17 am

   Hi

   Please suggest me how to bind the data bethought singleton.
   Code is given below.
   public static ShoppingCart GetShoppingCart() {
   // If the cart is not in the session, create one and put it there
   if (HttpContext.Current.Session["ASPNETShoppingCart"] == null) {
   ShoppingCart cart = new ShoppingCart();
   cart.Items = new List();
   HttpContext.Current.Session["ASPNETShoppingCart"] = cart;
   }

   return (ShoppingCart)HttpContext.Current.Session["ASPNETShoppingCart"];
   }

   Then, every time that you need to access it, replace this:

   ShoppingCart.Instance.AddItem(1);

   with this:

   ShoppingCart cart = ShoppingCart.getShoppingCart();
   cart.AddItem(1);

   kind regards

   Reply
2. asdas says:

   May 30, 2009 at 9:04 am

   not working even with singleton cut…

   Reply
3. hainv says:

   June 1, 2009 at 7:07 pm

   good code !Are you think that we are save Cart Items to Cookies ?

   Reply
4. hainv says:

   June 4, 2009 at 9:02 pm

   If do same you ,all customer will have same cart
   I’m modified:
   // The static constructor is called as soon as the class is loaded into memory
   public ShoppingCart()
   {
   // If the cart is not in the session, create one and put it there
   // Otherwise, get it from the session
   if (HttpContext.Current.Session["ShoppingCart"] == null)
   {
   _items = new List();
   HttpContext.Current.Session["ShoppingCart"] = _items;
   } else {
   _items = (List)HttpContext.Current.Session["ShoppingCart"];
   }
   }

   When you call method, you can do as :(new ShoppingCart()).Items;

   protected void BindData() {
   // Let’s give the data to the GridView and let it work!
   // The GridView will take our cart items one by one and use the properties
   // that we declared as column names (DataFields)
   gvShoppingCart.DataSource = (new ShoppingCart()).Items;
   gvShoppingCart.DataBind();
   }

   Reply
5. Jon says:

   June 27, 2009 at 2:43 am

   Hello Don,

   First off, thanks for providing this tutorial it has really aided my basic understanding of how to implement a shopping cart in ASP.NET.

   I’ve been trying to get rid of the Singleton implementation with the replacement code you supplied above however I am getting an “object reference not set to an instance of an object” error when running the source. This error gets thrown on the following statement’s completion:

   “if (HttpContext.Current.Session["ASPNETShoppingCart"] == null)”

   Here’s the modified code region that’s causing this problem

   #region New Implementation

   public static readonly ShoppingCart Instance;
   // Readonly properties can only be set in initialization or in a constructor
   public static ShoppingCart GetShoppingCart()
   {
   // If the cart is not in the session, create one and put it there
   if (HttpContext.Current.Session["ASPNETShoppingCart"] == null)
   {
   ShoppingCart cart = new ShoppingCart();
   cart.Items = new List();
   HttpContext.Current.Session["ASPNETShoppingCart"] = cart;
   }

   return (ShoppingCart)HttpContext.Current.Session["ASPNETShoppingCart"];
   }

   Any help is much appreciated, thanks again for the tutorial
   I’ve been unable to figure out how to fix this so any help is much appreciated.

   Reply
6. arjun says:

   July 20, 2009 at 11:50 pm

   Thanks, it helps really.
   But I want product list i.e ProdId,ProdName,Price from database then, how to do.
   please suggest me the way.

   Reply
7. Joel says:

   August 19, 2009 at 6:43 am

   Hello Don

   Thanks , is really good

   I need to show a produt list with : Id, Name, Price, Graph, and description , do you have some samples ?

   Regards

   Reply
8. Velibor says:

   September 5, 2009 at 8:25 am

   Works fine. That’s what I looking for. Maybe some AJAX in this could improve interaction without separately web page for viewing cart. Shopping cart could be visible from some pop-up window etc. :D

   Thanks for great tut.

   Reply
9. Joe says:

   October 11, 2009 at 10:44 am

   I dont really use ASP that much, but still pretty cool. :P

   Reply
10. Kris Crosby says:

    November 9, 2009 at 11:54 am

    To make this work with multiple users here is the complete solution to make this work for all of us who are not programmers. First in C. You need the change the following files from the example: ShoppingCart.cs per comments above. Then Default.aspx.cs per comments above. and last ViewCart.aspx.cs anytime the instance was called.

    Reply
    • Kris Crosby says:

      November 9, 2009 at 11:56 am

      //ViewCart.aspx.cs

      using System;
      using System.Web.UI.WebControls;
      /*************************** MEASURE LINE *****************************************/
      public partial class ViewCart : System.Web.UI.Page
      {
      protected void Page_Load(object sender, EventArgs e)
      {
      // ASP.NET keeps track of the state of all server controls
      // (like the GridView). Because of this, we don’t need to supply it with
      // the data every time the page loads. (No more re-checking checkboxes
      // that were checked or re-selecting the right item in the drop-down when
      // the page is submitted. It’s all done for you!)
      if (!IsPostBack)
      BindData();
      }

      protected void BindData()
      {
      // Let’s give the data to the GridView and let it work!
      // The GridView will take our cart items one by one and use the properties
      // that we declared as column names (DataFields)
      ShoppingCart cart = ShoppingCart.GetShoppingCart();
      gvShoppingCart.DataSource = cart.Items;
      gvShoppingCart.DataBind();
      }

      protected void gvShoppingCart_RowDataBound(object sender, GridViewRowEventArgs e) {
      // If we are binding the footer row, let’s add in our total

      if (e.Row.RowType == DataControlRowType.Footer) {
      ShoppingCart cart = ShoppingCart.GetShoppingCart();
      e.Row.Cells[3].Text = “Total: ” + cart.GetSubTotal().ToString(“C”);
      }
      }

      /**
      * This is the method that responds to the Remove button’s click event
      */
      protected void gvShoppingCart_RowCommand(object sender, GridViewCommandEventArgs e) {
      if (e.CommandName == “Remove”) {
      int productId = Convert.ToInt32(e.CommandArgument);
      ShoppingCart cart = ShoppingCart.GetShoppingCart();
      cart.RemoveItem(productId);
      }

      // We now have to re-setup the data so that the GridView doesn’t keep
      // displaying the old data
      BindData();
      }

      protected void btnUpdateCart_Click(object sender, EventArgs e) {
      foreach (GridViewRow row in gvShoppingCart.Rows) {
      if (row.RowType == DataControlRowType.DataRow) {
      // We’ll use a try catch block in case something other than a number is typed in
      // If so, we’ll just ignore it.
      try {
      // Get the productId from the GridView’s datakeys
      int productId = Convert.ToInt32(gvShoppingCart.DataKeys[row.RowIndex].Value);
      // Find the quantity TextBox and retrieve the value
      int quantity = int.Parse(((TextBox)row.Cells[1].FindControl(“txtQuantity”)).Text);
      ShoppingCart cart = ShoppingCart.GetShoppingCart();
      cart.SetItemQuantity(productId, quantity);
      } catch (FormatException) { }
      }
      }

      BindData();
      }
      }

      Reply
    • sean says:

      August 10, 2010 at 2:30 am

      tanx Kris. But the ShoppingCart.cs was not posted. can only see the Default.aspx.c and ViewCart.aspx.cs files. All the vb files are complete though.

      Tanx again. I used this shopping cart example for a website without knowing the bugs in it (now it’s misbehaving big time). I will try your fix as soon as I av the complete file.

      Reply
11. Kris Crosby says:

    November 9, 2009 at 11:57 am

    //Default.aspx.cs

    using System;

    public partial class _Default : System.Web.UI.Page {
    protected void Page_Load(object sender, EventArgs e) {

    }

    protected void btnAddShoes_Click(object sender, EventArgs e) {
    // Add product 1 to the shopping cart
    ShoppingCart cart = ShoppingCart.GetShoppingCart();
    cart.AddItem(1);
    // Redirect the user to view their shopping cart
    Response.Redirect(“ViewCart.aspx”);
    }

    protected void btnAddShirt_Click(object sender, EventArgs e) {
    ShoppingCart cart = ShoppingCart.GetShoppingCart();
    cart.AddItem(2);
    Response.Redirect(“ViewCart.aspx”);
    }

    protected void btnAddPants_Click(object sender, EventArgs e) {
    ShoppingCart cart = ShoppingCart.GetShoppingCart();
    cart.AddItem(3);
    Response.Redirect(“ViewCart.aspx”);
    }

    }

    Reply
12. Kris Crosby says:

    November 9, 2009 at 12:32 pm

    For VB, I used a C#->VB converter for the changed code for the same 3 files (ShoppingCart.vb,Default.aspx.vb and ViewCart.aspx.vb) Someone should really update the example files. A shopping cart for one person doesn’t make any sense and dispite the good intention of the author, if your going to teach something which establishes yourself as an expert, teach it right, and fix your mistakes acurately if they are discovered later. I am no programmer and I have to fix this code for all you programmers out there.

    Reply
    • Kris Crosby says:

      November 9, 2009 at 12:32 pm

      ‘ ShoppingCart.vb
      Imports Microsoft.VisualBasic

      ‘ The ShoppingCart class
      ‘ Holds the items that are in the cart and provides methods for their manipulation
      Public Class ShoppingCart

      #Region “Properties”

      Private _items As List(Of CartItem)
      Public Property Items() As List(Of CartItem)
      Get
      Return _items
      End Get
      Private Set(ByVal value As List(Of CartItem))
      _items = value
      End Set
      End Property

      #End Region

      #Region “Implementation”

      ‘ Readonly variables can only be set in initialization or in a constructor
      Public Shared ReadOnly Instance As ShoppingCart

      Public Shared Function GetShoppingCart() As ShoppingCart
      ‘ If the cart is not in the session, create one and put it there
      If HttpContext.Current.Session(“ASPNETShoppingCart”) Is Nothing Then
      Dim cart As New ShoppingCart()
      cart.Items = New List(Of CartItem)()
      HttpContext.Current.Session(“ASPNETShoppingCart”) = cart
      End If

      Return (DirectCast(HttpContext.Current.Session(“ASPNETShoppingCart”), ShoppingCart))

      End Function

      #End Region

      #Region “Item Modification Methods”

      ‘ AddItem() – Adds an item to the shopping
      Public Sub AddItem(ByVal productId As Integer)
      ‘ Create a new item to add to the cart
      Dim newItem = New CartItem(productId)

      ‘ If this item already exists in our list of items, increase the quantity
      ‘ Otherwise, add the new item to the list
      If Items.Contains(newItem) Then
      For Each item As CartItem In Items
      If item.Equals(newItem) Then
      item.Quantity += 1
      Return
      End If
      Next
      Else
      newItem.Quantity = 1
      Items.Add(newItem)
      End If

      End Sub

      ‘ SetItemQuantity() – Changes the quantity of an item in the cart
      Public Sub SetItemQuantity(ByVal productId As Integer, ByVal quantity As Integer)
      ‘ If we are setting the quantity to 0, remove the item entirely
      If quantity = 0 Then
      RemoveItem(productId)
      Return
      End If

      ‘ Find the item and update the quantity
      Dim updatedItem = New CartItem(productId)
      For Each item As CartItem In Items
      If item.Equals(updatedItem) Then
      item.Quantity = quantity
      Return
      End If
      Next
      End Sub

      ‘ RemoveItem() – Removes an item from the shopping cart
      Public Sub RemoveItem(ByVal productId As Integer)
      Dim removedItem = New CartItem(productId)

      For Each item As CartItem In Items
      If item.Equals(removedItem) Then
      Items.Remove(item)
      Return
      End If
      Next
      End Sub

      #End Region

      #Region “Reporting Methods”

      ‘ GetSubTotal() – returns the total price of all of the items before tax, shipping, etc.
      Public Function GetSubTotal() As Decimal
      Dim subTotal As Decimal = 0
      For Each item As CartItem In Items
      subTotal += item.TotalPrice
      Next

      Return subTotal
      End Function

      #End Region

      End Class

      Reply
    • Kris Crosby says:

      November 9, 2009 at 12:33 pm

      ‘ Default.aspx.vb
      ‘ The ShoppingCart class
      ‘ Holds the items that are in the cart and provides methods for their manipulation
      Public Class ShoppingCart

      #Region “Properties”

      Private _items As List(Of CartItem)
      Public Property Items() As List(Of CartItem)
      Get
      Return _items
      End Get
      Private Set(ByVal value As List(Of CartItem))
      _items = value
      End Set
      End Property

      #End Region

      #Region “Implementation”

      ‘ Readonly variables can only be set in initialization or in a constructor
      Public Shared ReadOnly Instance As ShoppingCart

      Public Shared Function GetShoppingCart() As ShoppingCart
      ‘ If the cart is not in the session, create one and put it there
      If HttpContext.Current.Session(“ASPNETShoppingCart”) Is Nothing Then
      Dim cart As New ShoppingCart()
      cart.Items = New List(Of CartItem)()
      HttpContext.Current.Session(“ASPNETShoppingCart”) = cart
      End If

      Return (DirectCast(HttpContext.Current.Session(“ASPNETShoppingCart”), ShoppingCart))

      End Function

      #End Region

      #Region “Item Modification Methods”

      ‘ AddItem() – Adds an item to the shopping
      Public Sub AddItem(ByVal productId As Integer)
      ‘ Create a new item to add to the cart
      Dim newItem = New CartItem(productId)

      ‘ If this item already exists in our list of items, increase the quantity
      ‘ Otherwise, add the new item to the list
      If Items.Contains(newItem) Then
      For Each item As CartItem In Items
      If item.Equals(newItem) Then
      item.Quantity += 1
      Return
      End If
      Next
      Else
      newItem.Quantity = 1
      Items.Add(newItem)
      End If

      End Sub

      ‘ SetItemQuantity() – Changes the quantity of an item in the cart
      Public Sub SetItemQuantity(ByVal productId As Integer, ByVal quantity As Integer)
      ‘ If we are setting the quantity to 0, remove the item entirely
      If quantity = 0 Then
      RemoveItem(productId)
      Return
      End If

      ‘ Find the item and update the quantity
      Dim updatedItem = New CartItem(productId)
      For Each item As CartItem In Items
      If item.Equals(updatedItem) Then
      item.Quantity = quantity
      Return
      End If
      Next
      End Sub

      ‘ RemoveItem() – Removes an item from the shopping cart
      Public Sub RemoveItem(ByVal productId As Integer)
      Dim removedItem = New CartItem(productId)

      For Each item As CartItem In Items
      If item.Equals(removedItem) Then
      Items.Remove(item)
      Return
      End If
      Next
      End Sub

      #End Region

      #Region “Reporting Methods”

      ‘ GetSubTotal() – returns the total price of all of the items before tax, shipping, etc.
      Public Function GetSubTotal() As Decimal
      Dim subTotal As Decimal = 0
      For Each item As CartItem In Items
      subTotal += item.TotalPrice
      Next

      Return subTotal
      End Function

      #End Region

      End Class

      Partial Class _Default
      Inherits System.Web.UI.Page

      Protected Sub btnAddShoes_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAddShirt.Click
      ‘ Add product 1 to the shopping cart
      Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
      cart.AddItem(1)

      ‘ Redirect the user to view their shopping cart
      Response.Redirect(“ViewCart.aspx”)
      End Sub

      Protected Sub btnAddShirt_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAddShorts.Click
      Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
      cart.AddItem(2)
      Response.Redirect(“ViewCart.aspx”)
      End Sub

      Protected Sub btnAddPants_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnAddShoes.Click
      Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
      cart.AddItem(3)
      Response.Redirect(“ViewCart.aspx”)
      End Sub
      End Class

      Reply
      • Ben Streissguth says:

        March 3, 2012 at 9:30 am

        Thanks to Kris for doing all of that. :) Just wanted to post the actual code for Default.aspx.vb as there seems to be a double post for the ShoppingCard class.

        Partial Class _Default
        Inherits System.Web.UI.Page

        Protected Sub btnAddShoes_Click(sender As Object, e As EventArgs)
        ‘ Add product 1 to the shopping cart
        Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
        cart.AddItem(1)
        ‘ Redirect the user to view their shopping cart
        Response.Redirect(“ViewCart.aspx”)
        End Sub

        Protected Sub btnAddShirt_Click(sender As Object, e As EventArgs)
        Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
        cart.AddItem(2)
        Response.Redirect(“ViewCart.aspx”)
        End Sub

        Protected Sub btnAddPants_Click(sender As Object, e As EventArgs)
        Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
        cart.AddItem(3)
        Response.Redirect(“ViewCart.aspx”)
        End Sub
        End Class
    • Kris Crosby says:

      November 9, 2009 at 12:33 pm

      ‘ ViewCart.aspx.vb

      Partial Class ViewCart
      Inherits System.Web.UI.Page

      Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
      ‘ ASP.NET keeps track of the state of all server controls
      ‘ (like the GridView). Because of this, we don’t need to supply it with
      ‘ the data every time the page loads. (No more re-checking checkboxes
      ‘ that were checked or re-selecting the right item in the drop-down when
      ‘ the page Is submitted. It’s all done for you!)

      If Not IsPostBack Then
      BindData()
      End If
      End Sub

      Protected Sub BindData()
      ‘ Let’s give the data to the GridView and let it work!
      ‘ The GridView will take our cart items one by one and use the properties
      ‘ that we declared as column names (DataFields)
      Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
      gvShoppingCart.DataSource = cart.Items
      gvShoppingCart.DataBind()
      End Sub

      Protected Sub gvShoppingCart_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs) Handles gvShoppingCart.RowDataBound
      ‘ If we are binding the footer row, let’s add in our total
      If e.Row.RowType = DataControlRowType.Footer Then
      Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
      e.Row.Cells(3).Text = “Total: ” & cart.GetSubTotal().ToString(“C”)
      End If
      End Sub

      ‘ This is the method that responds to the Remove button’s click event
      Protected Sub gvShoppingCart_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs) Handles gvShoppingCart.RowCommand
      If e.CommandName = “Remove” Then
      Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
      Dim productId = Convert.ToInt32(e.CommandArgument)
      cart.RemoveItem(productId)
      End If

      ‘ We now have to re-setup the data so that the GridView doesn’t keep displaying the old data
      BindData()
      End Sub

      End Class

      Reply
      • Ben Streissguth says:

        March 3, 2012 at 9:32 am

        The missing bit…

        Protected Sub btnUpdateCart_Click(sender As Object, e As EventArgs)
        For Each row As GridViewRow In gvShoppingCart.Rows
        If row.RowType = DataControlRowType.DataRow Then
        ‘ We’ll use a try catch block in case something other than a number is typed in
        ‘ If so, we’ll just ignore it.
        Try
        ‘ Get the productId from the GridView’s datakeys
        Dim productId As Integer = Convert.ToInt32(gvShoppingCart.DataKeys(row.RowIndex).Value)
        ‘ Find the quantity TextBox and retrieve the value
        Dim quantity As Integer = Integer.Parse(DirectCast(row.Cells(1).FindControl(“txtQuantity”), TextBox).Text)
        Dim cart As ShoppingCart = ShoppingCart.GetShoppingCart()
        cart.SetItemQuantity(productId, quantity)
        Catch generatedExceptionName As FormatException
        End Try
        End If
        Next

        BindData()
        End Sub
13. Yanayaya says:

    November 24, 2009 at 4:26 am

    Reading over the comments are we now at a point where this code works and can allow multiple users to place orders? Also I note that this tutorial uses static values in a drop down for price and item.

    What would be the coding to gather that information from a database??

    Reply
14. Rakesh Prasad says:

    December 3, 2009 at 3:31 am

    URGENT URGENT URGENT URGENT URGENT URGENT

    hi,
    This code is nice but it has big issue.
    My cart is sare to all user.I want one cart for one user not shareable cart.
    Plz help me!

    send code to amity.prasad@gmail.com

    Reply
15. BxBEnny says:

    December 13, 2009 at 12:36 am

    Tnx a lot. Why did u use Session? Is it the best way to solve security problem?

    Reply
16. Dan Petru says:

    December 17, 2009 at 3:21 pm

    Following Kris Crosby modiffications fixes everything

    Reply
17. magic says:

    December 19, 2009 at 11:51 am

    Nice and clean
    gj dude

    Reply
18. Ami Gill says:

    January 11, 2010 at 10:42 pm

    Nice Work…Thanks.

    Reply
19. narinder says:

    January 14, 2010 at 5:47 pm

    nice coding it solve my problem

    Reply
20. george hennessy says:

    January 14, 2010 at 10:15 pm

    I downloaded the source codes and pasted them into my shell files and they worked as advertised. I guess I’m learning through reverse engineering. I really like asp.net and C#, I just wish there were tutorials available that are “beginner-friendly” and professionally presented. Sigh…….

    Reply
21. mark says:

    February 10, 2010 at 1:00 am

    Hi everyone!
    Great tut! but how can i use it with sql server and import data in the gridview to the database?
    Please! help me!
    Thanks!

    Reply
22. james says:

    March 10, 2010 at 11:57 am

    Great! Question, where would i change the VB code to reflect say pricing groups? (i.e. 0-5 = $3.99, etc)?

    Great demo, great coding…thanks a million!

    Reply
23. Anders says:

    March 28, 2010 at 1:09 pm

    How do i get product info from database?

    Reply
24. ShinVieTNAm says:

    April 6, 2010 at 5:28 pm

    if (HttpContext.Current.Session[ASPNETShoppingCart] == null)
    {
    Instance = new ShoppingCart();
    Instance.Items = new List();
    HttpContext.Current.Session[ASPNETShoppingCart] = Instance;
    }
    else
    {
    Instance = (ShoppingCart)HttpContext.Current.Session[ASPNETShoppingCart];
    }

    ——————————————————- u wrong
    Client A , Client B ( or IE and Firefox

    Step 1 ..
    Client A Add Product ..
    Step 2 ..
    Client B submit View Card
    step 3 .. you will see the clients product B is added to Client A
    :D
    sorry . I dont know English ..

    Reply
25. grant says:

    April 8, 2010 at 2:21 pm

    Has anyone managed to populate the products from the database rather than use static ones?

    Reply
26. Nitropropain says:

    May 16, 2010 at 11:30 am

    it’s save my time. thx.

    Reply
27. influenceuk says:

    June 18, 2010 at 11:38 am

    I would like to know if we can use a Database on this code, and how do we impliment it? I see there is a product class so i am guessing we’d need to modify that to get the data?

    Could someone please post an update to get this working with a Database please?

    Reply
28. engchun says:

    June 27, 2010 at 8:51 pm

    thanks for the code sample , ShoppingCart cart = ShoppingCart.GetShoppingCart(); <– this is the line that call data from product.cs file right , if i am using mysql database , please advice convert code to mysql . thanks is advance

    Reply
29. George says:

    August 7, 2010 at 10:48 pm

    Hello! thanks for this tutorial but I have a problem! when I click on
    Add three KWL-JFE to cart
    open cart and there is a message like this

    Warning: Invalid argument supplied for foreach() in E:\xampp\htdocs\EXPEREMENTS\new\shopping-carts\shop_net\demo\cart_action.php on line 13

    what’s a problem?

    Reply
30. Vineet says:

    August 13, 2010 at 1:52 am

    Thanks Don for such a wonderful article, its really help me a lot, I was also very painful for me to remove singleton class, but i am again thankful for you regarding your solution ………….and also thanks to all other post and their author for understanding of the article

    Reply
31. Norm says:

    December 11, 2010 at 3:31 pm

    I am stil pretty new to ASP.NET. I would like to run this shopping cart code under .NET framework 2.0. What is the equivaent syntax for the folowing code? Please advice/

    public List Items { get; private set; }

    Changing to the following code will compile, but it will not work. You get Stackoverflow error.
    public List Items
    {
    get
    {
    return Items ;
    }

    set
    {
    Items = value;
    }
    }

    Reply
32. Norm says:

    December 14, 2010 at 12:28 am

    Kris Crosby,
    Somehow, I cannot convert yoru shopping cart.vb to C#. Do you have the Shopping cart.cs
    Norm

    Reply
33. Norm says:

    December 14, 2010 at 12:55 am

    It is alright. I got it all fixed now. Norm

    Reply
34. chade says:

    December 17, 2010 at 11:42 am

    It’s nice untill the client clicks on his browser back/forward button:(

    Reply
35. Mahaveer Singh says:

    January 5, 2011 at 9:31 pm

    Hi friends, need a help here

    When i tried the above example i was left with this error,

    ‘CartItem.Quantity.get’ must declare a body because it is not marked abstract or extern

    for the coing – ” public int Quantity { get; set; } ”

    I get this for all the properties that have left with empty get and set..

    Any idea what has to be done.

    Thanks in advance

    Reply
36. Marcelb says:

    January 17, 2011 at 8:00 am

    Hi there, to add an MSSQL database backend to this you need to replace the code below in product.vb

    Public Sub New(ByVal id As Integer)
    Me.Id = id
    If id = 1 Then
    Me.Price = 20.95
    Me.Description = “Shoes”
    ElseIf id = 2 Then
    Me.Price = 9.95
    Me.Description = “Shirt”
    ElseIf id = 3 Then
    Me.Price = 15.95
    Me.Description = “Pants”
    End If

    with

    Public Sub New(ByVal id As Integer)

    Dim conn As SqlConnection
    Dim cmdSELECT As SqlCommand
    Dim connString As String

    connString = ConfigurationManager.ConnectionStrings(“MarcelConnectionString”).ConnectionString
    conn = New SqlConnection(connString)
    cmdSELECT = New SqlCommand()
    cmdSELECT.Connection = conn
    cmdSELECT.CommandText = “selectInvent”
    cmdSELECT.CommandType = Data.CommandType.StoredProcedure
    cmdSELECT.Parameters.Add(New SqlParameter(“@id”, id))
    conn.Open()

    Dim rdr As SqlDataReader = cmdSELECT.ExecuteReader()

    Me.Price = 0
    Me.Description = “”
    Do While (rdr.Read())

    Me.Price = rdr.GetDecimal(rdr.GetOrdinal(“value”))
    Me.Description = rdr.GetString(rdr.GetOrdinal(“title”))

    Loop

    cmdSELECT.Dispose()
    cmdSELECT = Nothing
    conn.Close()
    conn = Nothing

    The code uses a stored procedure as below:

    CREATE PROCEDURE [dbo].[selectInvent]
    – Add the parameters for the stored procedure here
    @id as integer

    AS
    BEGIN
    – SET NOCOUNT ON added to prevent extra result sets from
    – interfering with SELECT statements.
    SET NOCOUNT ON;

    — Insert statements for procedure here
    select value, title
    FROM tbl_stockinventory
    WHERE id=@id

    END

    Hope this helps people….

    Reply
37. Allan Kendall says:

    January 21, 2011 at 7:25 am

    I was wondering how this solution could be adjusted to get the product information from a database. If you where to use a gridview and a sql datassource for example how would you code the back end so that the products where not hard coded into the pages.

    If you are going to make an online shop of anykind I find it hard to believe that you would hardcode stock into your pages, that just wouldnt happen. To make this better it would be nice if someone could perhaps demonstrate how we can use a database populated products gridview for stock selection.

    Anyone have any ideas?

    Reply
38. Michael Maloney says:

    March 23, 2011 at 12:20 pm

    I came across your code while training a new hire. The fix is to remove the static constructor and change the Instance variable to a property. Comment out the static constructor and change the instance variable as follows:

    public static ShoppingCart Instance
    {
    get
    {
    ShoppingCart c=null;
    if (HttpContext.Current.Session["ASPNETShoppingCart"] == null)
    {
    c = new ShoppingCart();
    c.Items = new List();
    HttpContext.Current.Session.Add(“ASPNETShoppingCart”, c);
    }
    else
    {
    c = (ShoppingCart)HttpContext.Current.Session["ASPNETShoppingCart"];
    }
    return c;
    }
    }

    Reply
39. dongitlhu says:

    April 21, 2011 at 11:29 pm

    how can I use a database with this code? I have a Product table and how to show data from this table?

    Reply
40. Rakesh says:

    April 25, 2011 at 11:37 am

    First of all, thanks for the helpful codes, it really help me in understanding the working of Shopping cart…
    But, I have a question….
    1. how to add Paypal or google checkout or etc for the paying the amount.
    2. How the number of products(Quantity) recorded in the database will be reduce….say I have 5 quantity of particular item in the database….After the successful checkout(buying) how it will be reduced to 4 or 3 or 2 or 0.

    Reply
41. Thomas says:

    April 29, 2011 at 11:10 am

    Hi,
    does anyone figure out what needs to be changed in this tutorial to make the cart not the same for all users?
    Now everyone sees the same cart, which is a bit pointless for online shopping…

    Thomas

    Reply
42. Rob says:

    May 17, 2011 at 8:02 am

    Nice cart however this isnt anything anyone can use in the real world. it would be nice if authors of articles like this could make realworld examples…if this was article would have been wired up to a database this would be one of the best articles written and for a simple and yet very good cart. also it would have gotten a whole lot more traffic than it has.

    I dont want to be a downer…so good job on this but if you trully wanna make tutorials and educate beginners give them real world examples…

    peace out,

    Reply
43. Felix åkerbäck says:

    May 23, 2011 at 12:01 pm

    Hey!

    Do you build it in Adobe Dreamweaver CS5? And do you build the other thing in Visual Express?

    Reply
44. KESHAV DEY says:

    June 4, 2011 at 6:30 am

    Hi,
    does anyone figure out what needs to be changed in this tutorial to make the cart not the same for all users?
    Now everyone sees the same cart, which is a bit pointless for online shopping…
    Shopping cart maintain its contain even browser is closed or reopen from any other computer
    using the same ip address . How to reset the cart when it open for the first time becomes a big problem in ur example..

    Reply
45. triad1984 says:

    June 15, 2011 at 1:30 pm

    I don’t think anyone wants to post a database solution for this cart becuase custom shopping carts are pretty big business and if we share it here everyone will run off and create turn key solutions off this one guy’s code and I’m sure no one here has the decency to offer royalties to the author. So, since the database piece is really the meat and potatoes of an online cart I would think it’s safe to say no one’s going to provide the code.

    Reply
46. Stam says:

    July 23, 2011 at 8:25 am

    Hi. Can anybody post ShiopCart.cs&? Thnx

    Reply
47. Bbaale says:

    August 6, 2011 at 6:31 am

    Thank you very much,God bless your family

    Reply
48. Neoteny says:

    August 9, 2011 at 3:32 am

    You have given a clear idea and specific direction for database which is going to help almost everyone. Thanks for sharing such an informative post. Nice information, many thanks to the author. It is incomprehensible to me now. You did a great job and your article is very informative.

    Reply
49. masoud says:

    August 12, 2011 at 5:30 am

    tanx for information

    Reply
50. Arun says:

    August 19, 2011 at 7:54 am

    How do i make it to use with different users.
    All users are having the same cart

    Reply