Using Assemblies with ASP.Net

Shopping Cart Demo

Shopping Cart

•Search and display product information

•Add item to cart

•View cart contents

•Check out

Shopping Cart Example

•Database:

–WebCustomer: CustID, CustName, Addr, Phone

–WebOrder: OrderID, CustID, OrderDate, CreditCardType,CreditCardNo

–WebLine: OrderID, PID, Pname, Price, Qty

–WebProduct: Pid, Pname, Price, UnitsInStock

•OrderID

•Login user using cookie

•Each item is modeled as a class, and items are collectedin a collection before added to the database.

Implementing Shopping Cart asClass

•Shopping Cart Properties:

–Public oid As String

–Public cid As String

–Public ODate As DateTime

–Public CreditCardType As String

–Public CreditCardNo as String

–Public CollCartLine As New ArrayList()

•Methods: AddItem, DeleteItem, ViewCart, CheckOut

•DetailLine Properties:

–OID

–PID

–Pname

–Price

–Qty

–Amount = Qty * Price

Adding a Class to a Website

•Website project:

–Class files must save in App_Code folder

–Right click Solution explorer and Choose AddASP.Net Folder

ShopCart Class

Public Class ShopCart

Public oid As String

Public cid As String

Public ODate As DateTime

Public CreditCardType As String

Public CreditCardNo As String

Public CollCartLine As New ArrayList()

Public ReadOnly Property CartTotal() As Double

Get

Dim item As New CartLine

Dim total As Double

Dim itemIndex As Integer

For Each item In CollCartLine

total = total + item.price * item.qty

CartTotal = total

End Get

End Property

AddItem Method

Public Sub AddItem(ByVal line As CartLine)

Dim item As New CartLine()

Dim incart As New Boolean()

incart = False

If CollCartLine.Count > 0 Then

For Each item In CollCartLine

If item.pid = line.pid Then

item.qty = line.qty

incart = True

Exit For

End If

If incart = False Then

CollCartLine.Add(line)

End If

End Sub

Public Sub deleteItem(ByVal deleteIndex As Integer)

CollCartLine.RemoveAt(deleteIndex)

End Sub

Public Sub checkOut()

Dim objLine As New CartLine()

Dim strSQL As String

Dim strConn As String

strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source = c:\sales2k.mdb"

Dim objConn As New OleDbConnection()

objConn.ConnectionString = strConn

Dim objComm As New OleDbCommand()

objConn.Open()

objComm.Connection = objConn

objComm.CommandType = CommandType.Text

strSQL = "insert into weborder values ('" & oid & "', '" & cid & "', #" & ODate.ToString & "#, '" &CreditCardType & "','" & CreditCardNo & "')"

objComm.CommandText = strSQL

objComm.ExecuteNonQuery()

For Each objLine In CollCartLine

strSQL = "insert into webline values ('" & objLine.oid & "', '" & objLine.pid & "', " & CStr(objLine.qty) &")"

objComm.CommandText = strSQL

objComm.ExecuteNonQuery()

End Sub

End Class

Shopping Cart Detail Line

Public Class CartLine

Private hiddenoid As String

Private hiddenpid As String

Private hiddenpname As String

Private hiddenprice As Double

Private hiddenqty As Integer

Public Property oid() As String

Get

oid = hiddenoid

End Get

Set(ByVal Value As String)

hiddenoid = Value

End Set

End Property

Public Property pid() As String

Get

pid = hiddenpid

End Get

Set(ByVal Value As String)

hiddenpid = Value

End Set

End Property

Public Property pname() As String

Get

pname = hiddenpname

End Get

Set(ByVal Value As String)

hiddenpname = Value

End Set

End Property

Public Property price() As Double

Get

price = hiddenprice

End Get

Set(ByVal Value As Double)

hiddenprice = Value

End Set

End Property

Public Property qty() As Integer

Get

qty = hiddenqty

End Get

Set(ByVal Value As Integer)

hiddenqty = Value

End Set

End Property

Public ReadOnly Property amount() As Double

Get

amount = qty * price

End Get

End Property

End Class

AddToCart Button EventProcedure

Protected Sub GridView1_SelectedIndexChanged(ByVal sender AsObject, ByVal e As System.EventArgs) HandlesGridView1.SelectedIndexChanged

MyCart = Session("MyCart")

Dim objLine As New CartLine()

objLine.oid = Session.SessionID

objLine.pid = GridView1.SelectedRow.Cells(0).Text

objLine.pname = GridView1.SelectedRow.Cells(1).Text

objLine.price = CDbl(GridView1.SelectedRow.Cells(2).Text)

objLine.qty =CInt(CType(GridView1.SelectedRow.Cells(4).Controls(1), TextBox).Text)

MyCart.AddItem(objLine)

Response.Write("number of items in cart:" &CStr(MyCart.CollCartLine.Count))

Session("MyCart") = MyCart

End Sub

Delete Button Procedure

Protected Sub GridView1_RowDeleting(ByVal sender AsObject, ByVal e AsSystem.Web.UI.WebControls.GridViewDeleteEventArgs)Handles GridView1.RowDeleting

MyCart.deleteItem(e.RowIndex)

Session("MyShopCart") = MyCart

GridView1.DataSource = MyCart.CollCartLine

GridView1.DataBind()

TextBox1.Text = MyCart.CartTotal.ToString

End Sub

CheckOut Procedure

Dim MyCart As New ShopCart()

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

'Put user code to initialize the page here

MyCart = Session("MyShopCart")

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e AsSystem.EventArgs) Handles Button1.Click

MyCart.oid = Session.SessionID

MyCart.cid = Session("cid")

MyCart.ODate = DateTime.Now()

MyCart.CreditCardType = RadioButtonList1.SelectedItem.Text

MyCart.CreditCardNo = TextBox1.Text

MyCart.checkOut()

Response.Write("Thank you for shopping atMy.Com")

Session.Abandon()

End Sub

Working with GridView ControlMurach’s ASP.Net Chap. 14

Adding Buttons to a Bound GridView

•Use GridView smart tag:

–Edit Columns

–Bound Fields, Command Fields, Template Fields

•Example:

–Drag a table from Server Explorer to create abound gridView.

–Use smart tag to choose Edit Columns

–Add command field:

•Edit

–Update, Cancel

–ASP.Net will execute the command automatically.

•Delete

•Select

Adding Command Fields to aBound GridView Created by Code

Rearrange the Fields Order

•Cancel the “Auto-Generate Fields” option

•Then add bound fields:

–For each bound field properties:

•Appearance:

–Header Text: This text will be used as column name

•Data:

–Data Field: for data binding

•Arrange fields order

Adding Edit/Update/Canceland Delete Buttons

–Use smart tag to choose Edit Columns

–Add command field:

•Edit

–Update, Cancel

•Delete

Adding Events for Edit/Update/Cance and Delete Buttons

Dim objDataSet As New DataSet

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) HandlesMe.Load

Dim strConn As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source = c:\salesDB.mdb"

Dim objConn As New OleDbConnection(strConn)

Dim strSQL As String

If Not Page.IsPostBack Then

strSQL = "select * from customer;"

Dim objAdapter As New OleDbDataAdapter(strSQL, objConn)

objAdapter.Fill(objDataSet, "customer")

GridView1.DataSource = objDataSet

GridView1.DataMember = "customer"

GridView1.DataBind()

Session("MyDs") = objDataSet

objConn.Close()

Else

objDataSet = Session("MyDs")

End If

End Sub

Protected Sub GridView1_RowCancelingEdit(ByVal sender As Object, ByVal e AsSystem.Web.UI.WebControls.GridViewCancelEditEventArgs) Handles GridView1.RowCancelingEdit

GridView1.EditIndex = -1

GridView1.DataSource = objDataSet

GridView1.DataMember = "customer"

GridView1.DataBind()

End Sub

Protected Sub GridView1_RowDeleting(ByVal sender As Object, ByVal e AsSystem.Web.UI.WebControls.GridViewDeleteEventArgs) Handles GridView1.RowDeleting

objDataSet.Tables("customer").Rows.RemoveAt(e.RowIndex)

GridView1.DataSource = objDataSet

GridView1.DataMember = "customer"

GridView1.DataBind()

End Sub

Protected Sub GridView1_RowEditing(ByVal sender As Object, ByVal e AsSystem.Web.UI.WebControls.GridViewEditEventArgs) Handles GridView1.RowEditing

Response.Write(e.NewEditIndex)

GridView1.EditIndex = e.NewEditIndex

GridView1.DataSource = objDataSet

GridView1.DataMember = "customer"

GridView1.DataBind()

End Sub

Protected Sub GridView1_RowUpdating(ByVal sender As Object, ByVal e AsSystem.Web.UI.WebControls.GridViewUpdateEventArgs) HandlesGridView1.RowUpdating

GridView1.EditIndex = -1

objDataSet.Tables("Customer").Rows(e.RowIndex).Item("Rating") =CType(GridView1.Rows(e.RowIndex).Cells(3).Controls(0), TextBox).Text

GridView1.DataSource = objDataSet

GridView1.DataMember = "customer"

GridView1.DataBind()

End Sub

Adding Textbox and Button and to aBound DataGrid

•GridView smart tag/Edit Columns:

–Template fields:

•HeaderText: This text will be used as columnname

•From the design view, click GridView’s smarttag and select Edit Template

•Drag a textbox to the template window.

Example

<asp:TemplateColumn HeaderText="Quantity">

<asp:TextBox id="txtQty" Width=70 runat="server"></asp:TextBox>

</ItemTemplate>

</asp:TemplateColumn>

<asp:TemplateColumn HeaderText="AddToCart">

<asp:Button Text="AddToCart" Runat="server"></asp:Button>

</ItemTemplate>

</asp:TemplateColumn>

Command Field: Select

•Select a row

•Trigger events:

–SelectedIndexChanged

•Retrieve the selected row:

–GridView1.SelectedRow

•Retrieve cells of the selected row:

–GridView1.SelectedRow.Cells(1).Text

•Retrieve data entered in the textbox:

–CType(GridView1.SelectedRow.Cells(4).Controls(1),TextBox).Text