shoppingcart.aspx

visual studio.net学习资料

<%@ Page Language="vb" %>
<%@ Register TagPrefix="Conference" TagName="Header" Src="_Header.ascx" %>
<%@ Register TagPrefix="Conference" TagName="Menu" Src="_Menu.ascx" %>

<script language="VB" runat="server">

    '*******************************************************
    '
    ' The Page_Load event on this page is used to load the
    ' ShoppingCart DataGrid *the first time* the page is 
    ' accessed.
    '
    ' Note that subsequent postbacks to the page *do not*
    ' reload the Datagrid.  Instead, we rely on the control's
    ' built-in viewstate management to rebuild the control
    ' on the server.
    '
    '*******************************************************

    Sub Page_Load(sender As Object, e As EventArgs) 
       
        ' Populate the shopping cart the first time the page is accessed.
        If Page.IsPostBack = False Then
           PopulateShoppingCartList()    
        End If
        
    End Sub
             
    '*******************************************************
    '
    ' The UpdateBtn_Click event is raised when a user clicks 
    ' the "update" button on the client.  The event handler 
    ' updates all items in the cart back to the database,
    ' and then repopulates the datagrid with the current
    ' cart contents.
    '
    '*******************************************************
             
    Sub UpdateBtn_Click(sender As Object, e As EventArgs)

        ' Update the Shopping Cart and then Repopulate the List
        UpdateShoppingCartDatabase()   
        PopulateShoppingCartList()
        
    End Sub

    '*******************************************************
    '
    ' The CheckoutBtn_Click event is raised when a user clicks 
    ' the "checkout" button on the client.  The event handler 
    ' updates all items in the cart back to the database,
    ' and then redirects the user to the checkout.aspx page
    '
    ' Other source code to examine:  
    '     Conference.ShoppingCartDB.GetItemCount() Method
    '
    '*******************************************************

    Sub CheckoutBtn_Click(sender As Object, e As EventArgs) 
    
        ' Update Shopping Cart
        UpdateShoppingCartDatabase()
      
        ' If cart is not empty, proceed on to checkout page
        Dim cart As New Conference.ShoppingCartDB

        ' Calculate shopping cart ID
        Dim cartId As String = cart.GetShoppingCartId()
      
        ' If the cart isn't empty, navigate to checkout page
        If cart.GetItemCount(cartId) <> 0 Then
            Page.Navigate("Checkout.aspx")
        Else
            MyError.Text = "You can't proceed to the Check Out page with an empty cart."
        End If
    
    End Sub

    '*******************************************************
    '
    ' The PopulateShoppingCartList helper method is used to
    ' dynamically populate a GridControl with the contents of
    ' the current user's shopping cart.
    '
    ' Other source code to examine:  
    '     Conference.ShoppingCartDB.GetShoppingCartID() Method
    '     Conference.ShoppingCartDB.GetItems() Method
    '     Conference.ShoppingCartDB.GetItemCount() Method
    '
    '*******************************************************

    Sub PopulateShoppingCartList() 
          
        Dim cart As New Conference.ShoppingCartDB
        
        ' Obtain current user's shopping cart ID              
        Dim cartId As String = cart.GetShoppingCartId()
        
        ' If no items, hide details and display message
        If cart.GetItemCount(cartId) = 0 Then
                   
            DetailsPanel.Visible = False
            MyError.Text = "There are currently no items in your shopping cart."
        
        Else
              
            ' Databind Gridcontrol with Shopping Cart Items  
            MyList.DataSource = cart.GetItems(cartId).Tables(0).DefaultView
            MyList.DataBind()
            
            'Update Total Price Label
            lblTotal.Text = System.String.Format( "{0:c}", cart.GetTotal(cartId))
        
        End If   
    
    End Sub
        
    '*******************************************************
    '
    ' The UpdateShoppingCartDatabase helper method is used to
    ' update a user's items within the shopping cart database
    ' using client input from the GridControl.
    '
    ' Other source code to examine:  
    '     Conference.ShoppingCartDB.GetShoppingCartID() Method
    '     Conference.ShoppingCartDB.GetItems() Method
    '     Conference.ShoppingCartDB.GetItemCount() Method
    '
    '*******************************************************
        
    Sub UpdateShoppingCartDatabase() 
          
        Dim cart As New Conference.ShoppingCartDB

        ' Obtain current user's shopping cart ID  
        Dim cartId As String = cart.GetShoppingCartId()
          
        ' Iterate through all rows within shopping cart list
        Dim i As Integer
        Dim quantityTxt As TextBox
        Dim lblProductID As Label
        Dim remove As CheckBox 
        
        For i = 0 To MyList.Items.Count-1
          
            ' Obtain references to row's controls
            Quantity = MyList.Items(i).FindControl("Quantity")
            ProductID = MyList.Items(i).FindControl("ProductID")      
            Remove = MyList.Items(i).FindControl("Remove")   

            ' Wrap in try/catch block to catch errors in the event that someone types in 
            ' a letter instead of a number for quantity
            Try    
                If CInt(Quantity.Text) = 0 Or Remove.Checked = True Then
                    cart.RemoveItem(cartId, CInt(ProductID.Text))
                Else
                    cart.UpdateItem(cartId, CInt(ProductID.Text), CInt(Quantity.Text))
                End If
            Catch
                MyError.Text = "There has been a problem with one or more of your inputs."
            End Try
            
        Next
        
    End Sub

</script>

<html>
    <head>
        <link rel="stylesheet" type="text/css" href="Conference.css">
    </head>
    
    <body background="images/sitebkgrd.gif" leftmargin="0" topmargin="0" rightmargin="0" bottommargin="0" marginheight="0" marginwidth="0">


    <!-- HEADER AND MENUS -->

    <table width="100%" border=0>

      <tr><td><Conference:Header runat="server"/></td></tr>
      <tr><td>
          <table width="100%" border=0>
            <tr><td valign="top">
                  <Conference:Menu runat="server"/>
                </td>
                <td>


    <!-- CONTENT -->


                
                    <table height="100%" valign="top" align="left" cellspacing=0 cellpadding=0 width="100%" border=0>
                    
                        <tr height="100%" valign="top">
                        
                            <td nowrap>
                            
                                <br>

                                <form runat="server">

                                    <img align=left width="32" src="images/1x1.gif">
        
                                    <table cellspacing=0 cellpadding=0 width="100%" border=0>
                                        <tr>
                                            <td class=ContentHeader>
                                                <img align=left height="32" width="60" src="images/1x1.gif">Shopping Cart<br>
                                            </td>
                                        </tr>
                                    </table>

                                    <img align="left" height="4" width="110" src="images/1x1.gif">
        
                                    <font color="red"><asp:Label id="MyError" class="ErrorText" maintainstate="False" runat="Server"/></font>
                                    <br>

                                    <img align="left" height="15" width="32" src="images/1x1.gif" border="0">

                                    <asp:panel id="DetailsPanel" runat=server>
                                    
                                        <img align="left" height="1" width="50" src="images/1x1.gif">
                                    
                                        <table valign=top height="100%" cellspacing=0 cellpadding=0 width="550" border=0>
                                        
                                            <tr valign=top height="100%">
                                            
                                                <td width="550">
                                                 
                                                    <asp:DataGrid id="MyList" runat="server" BorderColor="black" GridLines="Vertical" cellpadding="4" cellspacing="0" Font-Name="Verdana" Font-Size="8pt" ShowFooter="True" HeaderStyle-CssClass="CartListHeader" FooterStyle-CssClass="CartListFooter" ItemStyle-CssClass="CartListItem" AlternatingItemStyle-CssClass="CartListItemAlt" AutoGenerateColumns="False">
                                                    
                                                        <property name="Columns">
                                                                                
                                                          <asp:TemplateColumn HeaderText="Product&nbsp;ID">
                                                              <template name="ItemTemplate">
                                                                  <asp:Label id=ProductID runat="server" Text='<%# Container.DataItem("ProductID") %>'/>
                                                              </template>
                                                          </asp:TemplateColumn>  
                                                          
                                                          <asp:BoundColumn HeaderText="Product Name" DataField="ModelName"/>
                                                            
                                                          <asp:BoundColumn HeaderText="Model" DataField="ModelNumber"/>

                                                          <asp:TemplateColumn HeaderText="Quantity">
                                                              <template name="ItemTemplate">
                                                                  <asp:TextBox id=Quantity runat="server" Columns="4" Text='<%# Container.DataItem("Quantity") %>' width="40px" />
                                                              </template>
                                                          </asp:TemplateColumn>
                                                            
                                                          <asp:BoundColumn HeaderText="Price" DataField="UnitCost" DataFormatString="{0:c}" />
                                                          
                                                          <asp:BoundColumn HeaderText="Subtotal" DataField="ExtendedAmount" DataFormatString="{0:c}" />
                                                          
                                                          <asp:TemplateColumn HeaderText="Remove">
                                                              <template name="ItemTemplate">
                                                                  <center>
                                                                    <asp:CheckBox id=Remove runat="server" />
                                                                  </center>    
                                                              </template>
                                                          </asp:TemplateColumn>
                                                          
                                                        </property>

                                                    </asp:DataGrid>

                                                    <img src="Images/1x1.gif" width="350" height="1">
                                                    
                                                    <span class="TextBold"> Total: </span>
                                                    <asp:Label class="TextBold" ID="lblTotal" MaintainState="False" runat="server"/>
                                                    
                                                    <br>
                                                    <br>
                                                    
                                                  
                                                    <asp:button id="update" OnClick="UpdateBtn_Click" Text="Update your Shopping Cart" runat="server"/>
                                                        
                                                    <asp:button id="checkout" OnClick="CheckoutBtn_Click" Text="Final Check Out" runat="server"/>
                                                    
                                                    <br>
                                                </td>
                                            </tr>
                                        </table>
                                    </asp:panel>           
                                </form>         
                            </td>
                        </tr>
                    </table>



    <!-- END OF CONTENT -->  

                </td>

             </tr>

          </table>

      </td></tr>

    </table>


    <!-- END OF HEADER AND MENU -->        

    </body>
</html>