我刚刚问了一个问题，并相应地修改了我的代码。我写我的页面加载的方式有问题。我的目标是仅第一次初始化数组，然后继续递增它。你能帮我吗？这是我使用的代码：
Imports AjaxControlToolkit
Imports System.Data.SqlClient
Imports System.Configuration
Partial Class Shtick
Inherits System.Web.UI.Page
Dim conn As SqlConnection
Dim comm As SqlCommand
Dim reader As SqlDataReader
Dim purimConnection As String = ConfigurationManager.ConnectionStrings("Purim").ConnectionString
Dim ItemSelect As New ArrayList()
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If ItemSelect.Count > 0 Then
ItemSelect = New ArrayList()
Session("itemInCart") = ItemSelect
End If
If Not IsPostBack Then
FillShtickList()
End If
End Sub
Protected Sub FillShtickList()
Dim conn As SqlConnection
Dim comm As SqlCommand
Dim reader As SqlDataReader
Dim purimConnection As String = ConfigurationManager.ConnectionStrings("Purim").ConnectionString
conn = New SqlConnection(purimConnection)
comm = New SqlCommand("SELECT RTRIM(ProductPrice) AS Price, ProductName, ProductImage, ProductID, ProductDescription FROM Products", conn)
Try
conn.Open()
reader = comm.ExecuteReader()
ShtickDataList.DataSource = reader
ShtickDataList.DataBind()
reader.Close()
Finally
conn.Close()
End Try
End Sub
'Protected Sub ShtickDataList_ItemCreated(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ListViewItemEventArgs) Handles ShtickDataList.ItemCreated
' 'If e.Item.ItemType = ListItemType.Item Then
' ' Dim pce As ModalPopupExtender = e.Item.FindControl("PopupControlExtender1")
' ' Dim behaviorID As String
' ' behaviorID = "pce_" & e.Item.DataItemIndex
' ' pce.BehaviorID = behaviorID
' ' Dim img As Image = e.Item.FindControl("PI")
'item select = which item was selected
Dim Quantities As New ArrayList()
Dim itemQtyOrdered As Integer
Public Sub ShtickDataList_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.ListViewCommandEventArgs) Handles ShtickDataList.ItemCommand
If e.CommandName = "ViewCart" Then
Response.Redirect("~/ShoppingCart.aspx")
End If
If e.CommandName = "addToCart" Then
Dim itemQuantity As DropDownList = e.Item.FindControl("QuantityDropDown")
itemQtyOrdered = itemQuantity.SelectedValue
ItemSelect.Add(e.CommandArgument)
Quantities.Add(itemQtyOrdered)
Session("itemInCart") = ItemSelect
Session("quantities") = Quantities
viewInvoice()
End If
End Sub
Protected Sub viewInvoice()
Dim itemSelected As ArrayList = DirectCast(Session("itemInCart"), ArrayList)
Dim QuantityofItem As ArrayList = DirectCast(Session("quantities"), ArrayList)
Dim conn As SqlConnection
Dim comm As SqlCommand
Dim reader As SqlDataReader
Dim purimConnection2 As String = ConfigurationManager.ConnectionStrings("Purim").ConnectionString
conn = New SqlConnection(purimConnection2)
comm = New SqlCommand("SELECT ProductName FROM Products WHERE ProductID = @ProductID", conn)
'Dim i As Integer
'For i = 0 To ItemSelect.Count - 1
comm.Parameters.Add("@ProductID", Data.SqlDbType.Int)
comm.Parameters("@ProductID").Value = (ItemSelected.Count - 1)
'Next
Try
conn.Open()
reader = comm.ExecuteReader()
ViewCartlink.Text = "View Cart: (" & ItemSelected.Count & ")"
Finally
conn.Close()
End Try
End Sub
End Class
End Try
End Sub
End Class
= CType(Session("itemInCart"), ArrayList)
'al.Add(SS)
'Session.Add("itemInCart", al)
viewInvoice()
End If
End Sub
Protected Sub viewInvoice()
'Dim itemSelected As ArrayList = DirectCast(Session("itemInCart"), ArrayList)
'Dim QuantityofItem As ArrayList = DirectCast(Session("quantities"), ArrayList)
Dim conn As SqlConnection
Dim comm As SqlCommand
Dim reader As SqlDataReader
Dim purimConnection2 As String = ConfigurationManager.ConnectionStrings("Purim").ConnectionString
conn = New SqlConnection(purimConnection2)
comm = New SqlCommand("SELECT ProductName FROM Products WHERE ProductID = @ProductID", conn)
Dim i As Integer
For i = 0 To ItemSelect.Count - 1
comm.Parameters.Add("@ProductID", Data.SqlDbType.Int)
comm.Parameters("@ProductID").Value = ItemSelect(i)
Next
Try
conn.Open()
reader = comm.ExecuteReader()
ViewCartlink.Text = "View Cart: (" & ItemSelect.Count & ")"
Finally
conn.Close()
End Try
End Sub
End Class
M(ProductPrice) AS Price, ProductID, ProductName FROM Products WHERE ProductID = @ProductID", conn)
comm = New SqlCommand("Insert into orders (UserID, ProductID, quantity) values (1, @ProductID, @Quantity)", conn)
comm.Parameters.Add("@ProductID", Data.SqlDbType.Int)
comm.Parameters("@ProductID").Value = item
comm.Parameters.Add("@Quantity", Data.SqlDbType.Int)
comm.Parameters("@Quantity").Value = qty
'Dim i As Integer
'For i = 0 To ItemSelect.Length - 1
' comm.Parameters.Add("@ProductID", Data.SqlDbType.Int)
' comm.Parameters("@ProductID").Value = ItemSelect(i)
'Next
Try
conn.Open()
comm.ExecuteNonQuery()
'reader = comm.ExecuteReader()
'ShoppingList.DataSource = reader
'ShoppingList.DataBind()
'reader.Close()
Finally
conn.Close()
End Try
End Sub