Shopping Cart Example Code In ASP.NET C# VB.NET GridView

Creating Shopping Cart Example Code In Asp.Net 2.0,3.5,40 With Gridview C#.NET,VB.NET. I'm using GridView and DataList controls to create Products page and Product Details page in online shopping cart example




First of all we need to create a ShoppingCart class, for this right click on solution explorer and add new class, name it ShoppingCart.cs
Write this code in ShoppingCart.cs class

namespace ShoppingCartExample
{
    /// <summary>
    /// Summary description for ShoppingCart
    /// </summary>
    [Serializable] 
    public class CartItem
    {
        private int _productID;
        private string _productName;
        private string _imageUrl;
        private int _quantity;
        private double _price;
        private double _subTotal;

        public CartItem()
        { 
        }
        public CartItem(int ProductID, string ProductName, 
              string ImageUrl, int Quantity, double Price)
        {
            _productID = ProductID;
            _productName = ProductName;
            _imageUrl = ImageUrl;
            _quantity = Quantity;
            _price = Price;
           _subTotal = Quantity * Price;
        }
        public int ProductID
        {
            get
            {
                return _productID;
            }
            set
            {
                _productID = value;
            }
        }
         public string ProductName
         {
            get { return _productName; }
            set { _productName = value; }
         }
         public string ImageUrl
         {
             get { return _imageUrl; }
             set { _imageUrl = value; }
         }

         public int Quantity
         {
             get { return _quantity; }
             set { _quantity = value; }
         }

         public double Price
         {
             get { return _price; }
             set { _price = value; }
         }

         public double SubTotal
         {
             get { return _quantity * _price; }
            
         }
    }
    [Serializable]
    public class Cart
    {
        private DateTime _dateCreated;
        private DateTime _lastUpdate;
        private List<CartItem> _items;

        public Cart()
        {
            if (this._items == null)
            {
                this._items = new List<CartItem>();
                this._dateCreated = DateTime.Now;
            }
        }

        public List<CartItem> Items
        {
         get { return _items;}
        set { _items = value;}
        }

        public void Insert(int ProductID, double Price, 
        int Quantity, string ProductName, string ImageUrl)
        {
            int ItemIndex = ItemIndexOfID(ProductID);
            if (ItemIndex == -1)
            {
                CartItem NewItem = new CartItem();
                NewItem.ProductID = ProductID;
                NewItem.Quantity = Quantity;
                NewItem.Price = Price;
                NewItem.ProductName = ProductName;
                NewItem.ImageUrl = ImageUrl;
                _items.Add(NewItem);
            }
            else
            {
                _items[ItemIndex].Quantity += 1;
            }
            _lastUpdate = DateTime.Now;
        }

        public void Update(int RowID, int ProductID, 
                         int Quantity, double Price)
        {
            CartItem Item = _items[RowID];
            Item.ProductID = ProductID;
            Item.Quantity = Quantity;
            Item.Price = Price;
            _lastUpdate = DateTime.Now;
        }

        public void DeleteItem(int rowID)
        {
            _items.RemoveAt(rowID);
            _lastUpdate = DateTime.Now;
        }

        private int ItemIndexOfID(int ProductID)
        {
            int index = 0;
            foreach (CartItem item in _items)
            {
                if (item.ProductID == ProductID)
                {
                    return index;
                }
                index += 1;
            }
            return -1;
        }

        public double Total
        {
            get
            {
                double t = 0;
                if (_items == null)
                {
                    return 0;
                }
                foreach (CartItem Item in _items)
                {
                    t += Item.SubTotal;
                }
                return t;
            }
        }
 
    }
}

Now to create Products page, add a new webform and name it Products.aspx, add sqldataSource and configure it for select statement,
read this for how to configure SqlDataSource
Add a DataList Control on the page and make SqlDataSource1 it's source.
Configure Datalist according to below mentioned source

<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<div>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT [ProductID], [Name], [Description], 
               [Price], [ImageUrl] FROM [Products]">
</asp:SqlDataSource>
</div>

<asp:DataList ID="DataList1" runat="server" 
              DataSourceID="SqlDataSource1" 
              RepeatColumns="4"
              RepeatDirection="Horizontal">
<ItemTemplate>
<asp:ImageButton ID="ImageButton1" runat="server" 
ImageUrl='<%# Eval("ImageUrl", "Images\\thumb_{0}") %>' 
PostBackUrl='<%# Eval("ProductID", 
"ProductDetails.aspx?ProductID={0}") %>' />
<br />
<asp:Label ID="NameLabel" runat="server" 
           Text='<%# Eval("Name") %>'>
</asp:Label>
<asp:Label ID="PriceLabel" runat="server" 
           Text='<%# Eval("Price", "{0:C}") %>'>
</asp:Label><br />
<br />
<br />
</ItemTemplate>
</asp:DataList><br />
<asp:HyperLink ID="CartLink" runat="server" 
               NavigateUrl="~/UserCart.aspx">
               View Shopping Cart
</asp:HyperLink><br />
</form>

Now add a new webform and name it ProductDetails.aspx , this page is used for showing details for selected product from product catalog page, again add a SqlDataSource and DataList Control on this page and configure them according to source shown below, this time datalist is populated using QueryString Parameters.

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT [ProductID], [Name], [Description], 
               [Price], [ImageUrl] FROM [Products] 
               WHERE ([ProductID] = @ProductID)">
    <SelectParameters>
    <asp:QueryStringParameter Name="ProductID" 
                              QueryStringField="ProductID" 
                              Type="Decimal" />
    </SelectParameters>
</asp:SqlDataSource>
</div>

<asp:DataList ID="DataList1" runat="server" 
              DataSourceID="SqlDataSource1">
<ItemTemplate>
  <asp:Image ID="Image1" runat="server" 
       ImageUrl='<%# Eval("ImageUrl","~/Images\\{0}") %>'/>
  <asp:Label ID="ImageUrlLabel" runat="server" 
             Text='<%# Eval("ImageUrl") %>' 
             Visible="False">
  </asp:Label><br />
  <asp:Label ID="NameLabel" runat="server" 
             Text='<%# Eval("Name") %>'>
  </asp:Label><br />
  <asp:Label ID="DescriptionLabel" runat="server" 
             Text='<%# Eval("Description") %>'>
  </asp:Label><br />
  <asp:Label ID="PriceLabel" runat="server" 
             Text='<%# Eval("Price", "{0:##0.00}" ) %>'>
  </asp:Label><br />
</ItemTemplate>
</asp:DataList><br />
<asp:Button ID="btnAdd" runat="server" OnClick="Button1_Click" 
                        Text="Add to Cart" /><br /><br />
<asp:HyperLink ID="HyperLink1" runat="server" 
               NavigateUrl="~/Products.aspx">
               Return to Products Page
</asp:HyperLink>

Write this code in C# code behind of ProductDetails.aspx page

protected void Button1_Click(object sender, EventArgs e)
{
  double Price = double.Parse(((Label)
    DataList1.Controls[0].FindControl("PriceLabel")).Text);
  string ProductName = ((Label)
    DataList1.Controls[0].FindControl("NameLabel")).Text;
  string ProductImageUrl = ((Label)
   DataList1.Controls[0].FindControl("ImageUrlLabel")).Text;
int ProductID = int.Parse(Request.QueryString["ProductID"]);
if (Profile.SCart == null)
{
  Profile.SCart = new ShoppingCartExample.Cart();
}
  Profile.SCart.Insert
      (ProductID, Price, 1, ProductName, ProductImageUrl);
  Server.Transfer("Products.aspx");
}

Now right click on solution explorer and add new web user control, name it CartControl.ascx
In design view of this control add a new GridView control and a label below gridview, html shource of this control should look like this

<%@ Control Language="C#" AutoEventWireup="true" 
            CodeFile="CartControl.ascx.cs" 
            Inherits="CartControl" %>
<asp:GridView ID="grdCart" runat="server" 
              AutoGenerateColumns="False" 
              DataKeyNames="ProductID" 
              OnRowCancelingEdit="grdCart_RowCancelingEdit" 
              OnRowDeleting="grdCart_RowDeleting" 
              OnRowEditing="grdCart_RowEditing" 
              OnRowUpdating="grdCart_RowUpdating">
<Columns>
<asp:TemplateField>
    <ItemTemplate>
    <asp:Image ID="Image1" runat="server" 
    ImageUrl='<%#Eval("ImageUrl","~/Images/thumb_{0}")%>'/>
    </ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="ProductName" 
                HeaderText="Product" ReadOnly="True"/>
<asp:BoundField DataField="Quantity" HeaderText="Quantity"/>
<asp:BoundField DataField="Price" DataFormatString="{0:c}" 
                HeaderText="Price" ReadOnly="True" />
<asp:BoundField DataField="SubTotal" DataFormatString="{0:c}" 
                HeaderText="Total" ReadOnly="True" />
<asp:CommandField ShowDeleteButton="True" 
                  ShowEditButton="True"/>
</Columns>
<EmptyDataTemplate>
Your Shopping Cart is empty, add items
<a href="Products.aspx">Add Products</a>
</EmptyDataTemplate>
</asp:GridView>
<asp:Label ID="TotalLabel" runat="server"></asp:Label>

Open web.config file and add this section for enabling anonymous users to add items to cart

<system.web>
  <authorization>
   <allow users="?" />
   <allow roles="admin" />
  </authorization>
  <roleManager enabled="true" />
  <authentication mode="Forms" />
          <compilation debug="true">
            </compilation>
        </system.web>
  <system.web>
    <anonymousIdentification enabled="true"/>
    <profile enabled="true">
      <properties>
       <add name="SCart" serializeAs="Binary" 
            type="ShoppingCartExample.Cart" 
            allowAnonymous="true"/>
      </properties>
    </profile>
  </system.web>

Now go to code behnd of CartControl.ascx and write this code

protected void Page_Load(object sender, EventArgs e)
    {
        if (Profile.SCart == null)
        {
            Profile.SCart = new ShoppingCartExample.Cart();
        }
        if (!Page.IsPostBack)
        {
            ReBindGrid();
        }
        if(Profile.SCart.Items == null)
        {
            TotalLabel.Visible = false;
        }
    }
    protected void grdCart_RowEditing
                 (object sender, GridViewEditEventArgs e)
    {
        grdCart.EditIndex = e.NewEditIndex;
        ReBindGrid();
    }
    protected void grdCart_RowUpdating
               (object sender, GridViewUpdateEventArgs e)
    {
        TextBox txtQuantity = (TextBox)
        grdCart.Rows[e.RowIndex].Cells[2].Controls[0];
        int Quantity = Convert.ToInt32(txtQuantity.Text);
        if (Quantity == 0)
        {
            Profile.SCart.Items.RemoveAt(e.RowIndex);
        }
        else
        {
            Profile.SCart.Items[e.RowIndex].Quantity 
                                         = Quantity;
        }
        grdCart.EditIndex = -1;
        ReBindGrid();
    }
    protected void grdCart_RowCancelingEdit
             (object sender, GridViewCancelEditEventArgs e)
    {
        grdCart.EditIndex = -1;
        ReBindGrid();
    }
    protected void grdCart_RowDeleting
                 (object sender, GridViewDeleteEventArgs e)
    {
        Profile.SCart.Items.RemoveAt(e.RowIndex);
        ReBindGrid();
    }
    private void ReBindGrid()
    {
        grdCart.DataSource = Profile.SCart.Items;
        DataBind();
        TotalLabel.Text = string.Format("Total:{0,19:C}", 
                                     Profile.SCart.Total);
    }

Now add Global Application Class (Global.asax) by right clicking on solution explorer > add new Item. and write code mentioned below in it.

void Profile_OnMigrateAnonymous(object sender, ProfileMigrateEventArgs e)
    {
        ProfileCommon anonymousProfile = Profile.GetProfile(e.AnonymousID);
        if (anonymousProfile.SCart != null)
        {
            if (Profile.SCart == null)
                Profile.SCart = new ShoppingCartExample.Cart();

            Profile.SCart.Items.AddRange(anonymousProfile.SCart.Items);

            anonymousProfile.SCart = null;
        }

        ProfileManager.DeleteProfile(e.AnonymousID);
        AnonymousIdentificationModule.ClearAnonymousIdentifier();
    }
       

Add another webform and name it UserCart.aspx, in design view of this page drag the CartControl we've just created and put a hyperlink for going back to products cataloge page

Tha's it , build and run the application
Have fun

Download the sample code attached