asked on

How to Maintain checkbox state across datagrid pages?

I am working on an eccomerce application which displays products in a datagrid. This datagrid is paged and one of the columns is a checkbox. The problem is I cant seem to keep the checkbox's state across datagrid pages. HELP! Here is what I have so far:

Code Behind:
---------------
Imports StoreFront.BusinessRule
Imports StoreFront.BusinessRule.Management
Imports StoreFront.SystemBase
Imports System.Text
Imports System.Web.UI.Page

Public MustInherit Class n_FeaturedProductAdmin
Inherits System.Web.UI.UserControl

Private Product1 As New SystemBase.NFeaturedProductBase
Private Product2 As New SystemBase.NFeaturedProductBase
Private Product3 As New SystemBase.NFeaturedProductBase
Private Product4 As New SystemBase.NFeaturedProductBase
Protected WithEvents dgProducts As System.Web.UI.WebControls.DataGrid
Protected WithEvents btnUpdate As System.Web.UI.WebControls.Button
Protected WithEvents lblMessage As System.Web.UI.WebControls.Label
Protected CheckBox As System.Web.UI.WebControls.CheckBox
Dim oSet As New SystemBase.NFeaturedProductBaseSet
Protected WithEvents Literal1 As System.Web.UI.WebControls.Literal

#Region " Web Form Designer Generated Code "

'This call is required by the Web Form Designer.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

End Sub
Protected WithEvents Product4Description As System.Web.UI.WebControls.HyperLink
Protected WithEvents imgProduct4 As System.Web.UI.WebControls.Image
Protected WithEvents Product3Description As System.Web.UI.WebControls.HyperLink
Protected WithEvents imgProduct3 As System.Web.UI.WebControls.Image
Protected WithEvents Product2Description As System.Web.UI.WebControls.HyperLink
Protected WithEvents imgProduct2 As System.Web.UI.WebControls.Image
Protected WithEvents Product1Description As System.Web.UI.WebControls.HyperLink
Protected WithEvents imgProduct1 As System.Web.UI.WebControls.Image
Protected WithEvents Label1 As System.Web.UI.WebControls.Label
Protected WithEvents ddlCategory As System.Web.UI.WebControls.DropDownList

'NOTE: The following placeholder declaration is required by the Web Form Designer.
'Do not delete or move it.
Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
'CODEGEN: This method call is required by the Web Form Designer
'Do not modify it using the code editor.
InitializeComponent()
End Sub

#End Region

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
If Not Page.IsPostBack Then
ddlCategory.SelectedIndex = 0
End If

Session("LandingPageCategoryID") = 1
Dim CategoryID As Integer = Session("LandingPageCategoryID")
GetFeaturedItems(CategoryID)
GetProductDescriptionsETC()
If Not Page.IsPostBack Then
GetTopLevelCategories()
End If

dgProducts.DataSource = CType(Session("datasource"), DataSet)
dgProducts.DataBind()
End Sub

Private ReadOnly Property CompletedList() As Hashtable
Get
Dim hashtable As Hashtable
If IsNothing(ViewState("Completed")) Then
hashtable = New Hashtable
ViewState("Completed") = hashtable
Else
hashtable = CType(ViewState("Completed"), Hashtable)
End If
Return hashtable
End Get
End Property

Public Sub GetTopLevelCategories()
Dim CategoryMGR As New BusinessRule.CCategories
Dim oCategories As New SystemBase.CCategory
Dim oCatArray As ArrayList
oCatArray = CategoryMGR.ParantCategories()
ddlCategory.DataSource = oCatArray.ToArray
ddlCategory.DataBind()
End Sub

Public Function GetProductID(ByVal FeaturedProductNumber As Integer) As Integer
Dim ProductID As Integer

Select Case FeaturedProductNumber
'Hard Coded for now, should get id from db
Case 1
ProductID = Product1.UID()

Case 2
ProductID = Product2.UID()
Case 3
ProductID = Product3.UID()
Case 4
ProductID = Product4.UID()

End Select
Return ProductID
End Function

Public Sub GetProductDescriptionsETC()

Product1Description.Text = Product1.Name
Product1Description.NavigateUrl = "http://servername/estore_tech/detail.aspx?ID=" & Product1.UID
imgProduct1.ImageUrl = Product1.ImageSmallPath

Product2Description.Text = Product2.Name
Product2Description.NavigateUrl = "http://servername/estore_tech/detail.aspx?ID=" & Product2.UID
imgProduct2.ImageUrl = Product2.ImageSmallPath

Product3Description.Text = Product3.Name
Product3Description.NavigateUrl = "http://servername/estore_tech/detail.aspx?ID=" & Product3.UID
imgProduct3.ImageUrl = Product3.ImageSmallPath

Product4Description.Text = Product4.Name
Product4Description.NavigateUrl = "http://servername/estore_tech/detail.aspx?ID=" & Product4.UID
imgProduct4.ImageUrl = Product4.ImageSmallPath

End Sub

Public Sub GetFeaturedItems(ByVal CategoryID As Integer)
Dim FeaturedProductMGR As New BusinessRule.FeaturedProducts.NFeaturedProduct

Dim oFeaturedItem As New SystemBase.NFeaturedProductBase
oSet = FeaturedProductMGR.LoadFeaturedProducts(CategoryID)
Product1 = oSet(0)
Product2 = oSet(1)
Product3 = oSet(2)
Product4 = oSet(3)
End Sub

Private Sub ddlCategory_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ddlCategory.SelectedIndexChanged
BindData(dgProducts.CurrentPageIndex)

End Sub

Public Sub NewPage(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridPageChangedEventArgs) Handles dgProducts.PageIndexChanged

ProcessCheckBoxes()
BindData(e.NewPageIndex)
dgProducts.CurrentPageIndex = e.NewPageIndex

End Sub
Public Sub BindData(ByVal val As Integer)
'Get the First Level Children for the selected Landing Page Category
Dim CategoryMGR As New BusinessRule.CCategories
Dim products As New FeaturedProducts.NFeaturedProduct
Dim c As New CXMLCategoryList
Dim oCatArray As ArrayList
Dim x As Integer
Dim oArray As ArrayList

oCatArray = CategoryMGR.GetFirstLevelChildren(ddlCategory.SelectedValue)
'Get Products by Category for each of the child categories

For x = 0 To oCatArray.Count - 1
c = oCatArray(x)
oArray = CategoryMGR.GetAllProductsByCategory(c.ID) 'the productid is returned.
Next

'the uid in the product table is the productid from above
' We need to grab the product data for each item in the arraylist (each product)
Dim ds As New DataSet

ds.Tables.Add("Products")
'GetProductData
ds = products.LoadProductsForCategories(oArray)
dgProducts.CurrentPageIndex = val
dgProducts.DataKeyField = "UID"
dgProducts.DataSource = ds
Session("datasource") = ds
dgProducts.DataBind()

End Sub

Private Sub ProcessCheckBoxes()
Dim checkBox As System.Web.UI.WebControls.CheckBox
Dim key As String
For Each item As DataGridItem In dgProducts.Items
Select Case item.ItemType
Case ListItemType.Item, ListItemType.AlternatingItem
checkBox = CType(item.Controls(2).FindControl("chkSelected"), System.Web.UI.WebControls.CheckBox)
If Not IsNothing(checkBox) Then
key = dgProducts.DataKeys(item.ItemIndex).ToString()
If checkBox.Checked = True And (CompletedList.ContainsKey(key) = False Or CType(CompletedList(key), Boolean) = False) Then
CompletedList(key) = True
ElseIf checkBox.Checked = False And CompletedList.ContainsKey(key) = True And CType(CompletedList(key), Boolean) = True Then
CompletedList(key) = False
End If
End If

End Select

Next
End Sub

Public Function TODouble(ByVal val As String) As Double
Return FormatCurrency(val, 2, TriState.True, TriState.True, TriState.True)

End Function

Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click

Dim sb As StringBuilder = New StringBuilder
ProcessCheckBoxes()
sb.Append("<table>")
sb.Append("<tr><th>Order Checked</th></tr>")
For Each entry As DictionaryEntry In CompletedList
If CType(entry.Value, Boolean) = True Then
sb.AppendFormat("<tr><td>{0}</td></tr>", entry.Key)
End If
Next
sb.Append("</table>")
Literal1.Text = sb.ToString()

'check if more than 4 have been Selected

Dim nCount As Integer
For Each dgItem As DataGridItem In dgProducts.Items
CheckBox = CType(dgItem.FindControl("chkSelected"), CheckBox)
If CheckBox.Checked = True Then
nCount += 1
End If
If nCount >= 4 Then
lblMessage.Text = "You may only select 4 items to be featured"
Exit Sub

End If

Next
nCount = 0
'Update the featured items for the selected toplevel category
Dim products As New FeaturedProducts.NFeaturedProduct
Dim oFeaturedProduct As New SystemBase.NFeaturedProductBase

For Each dgItem As DataGridItem In dgProducts.Items
CheckBox = CType(dgItem.FindControl("chkSelected"), CheckBox)
If CheckBox.Checked = True Then
nCount += 1
If nCount <= 4 Then
Dim FeaturedProductMGR As New BusinessRule.FeaturedProducts.NFeaturedProduct

Dim oFeaturedItem As New SystemBase.NFeaturedProductBase
oFeaturedItem.CategoryID = ddlCategory.SelectedValue
oFeaturedItem.FeaturedProductNumber = nCount
oFeaturedItem.ImageSmallPath = CType(dgItem.Cells(5).Text, String)
oFeaturedItem.Name = CType(dgItem.Cells(1).Text, String)
oFeaturedItem.UID = CType(dgItem.Cells(0).Text, Integer)
FeaturedProductMGR.SaveFeaturedProducts(oFeaturedItem)
End If

End If

Next

End Sub

End Class

and the client side page:
<%@ Control Language="vb" AutoEventWireup="false" Codebehind="n_FeaturedProductAdmin.ascx.vb" Inherits="StoreFront.StoreFront.n_FeaturedProductAdmin" TargetSchema="http://schemas.microsoft.com/intellisense/ie5" %>
<TABLE id="Table1" style="WIDTH: 736px; HEIGHT: 296px" width="736" border="1">
      <TR>
            <TD vAlign="top" width="20%"><asp:label id="Label1" Width="208px" runat="server">Select A Landing Page Category</asp:label><asp:dropdownlist id="ddlCategory" Width="208px" runat="server" AutoPostBack="True" DataValueField="ID"
                        DataTextField="Name"></asp:dropdownlist></TD>
            <TD vAlign="bottom" align="right" width="30%" colSpan="2" rowSpan="1"><asp:datagrid id="dgProducts" Width="568px" runat="server" AutoGenerateColumns="False" PageSize="10"
                        AllowPaging="True" OnPageIndexChanged="NewPage" DataKeyField="UID" PagerStyle-Mode="NumericPages" EnableViewState=True>
                        <Columns>
                              <asp:TemplateColumn HeaderText="Selected">
                                    <ItemTemplate>
                                          <asp:CheckBox ID="chkSelected" Runat="server" ></asp:CheckBox>
                                    </ItemTemplate>
                              </asp:TemplateColumn>


                              <asp:BoundColumn Visible="False" DataField="UID"></asp:BoundColumn>
                              <asp:BoundColumn DataField="Name" HeaderText="Name" ItemStyle-Width="320px"></asp:BoundColumn>
                              <asp:BoundColumn DataField="Code" HeaderText="Code" ItemStyle-Width="60px"></asp:BoundColumn>
                              <asp:BoundColumn DataField="Price" HeaderText="Price" DataFormatString="{0:C}"></asp:BoundColumn>
                              <asp:BoundColumn DataField="Cost" HeaderText="Cost" DataFormatString="{0:C}"></asp:BoundColumn>
                              <asp:TemplateColumn HeaderText="Image">
                                    <ItemTemplate>
                                          <img src='http://almira/estore_tech/<%# DataBinder.Eval(Container.DataItem,"ImageSmallPath") %>' border=0 id="ThumbImg">
                                    </ItemTemplate>
                              </asp:TemplateColumn>
                        </Columns>
                        <PagerStyle PageButtonCount="10"></PagerStyle>
                  </asp:datagrid><asp:button id="btnUpdate" runat="server" Text="Update Featured Products"></asp:button></TD>
            <TD vAlign="top" align="center" width="30%"></TD>
            <TD width="20%"></TD>
      </TR>
      <TR>
            <TD vAlign="top" width="20%"></TD>
            <TD vAlign="bottom" align="center" width="30%" colSpan="2"> Featured Products
                  for the Selected Category</TD>
            <TD vAlign="top" align="center" width="30%"></TD>
            <TD width="20%"></TD>
      </TR>
      <TR>
            <TD width="20%"></TD>
            <TD vAlign="top" align="center" width="30%"><A
href="http://servername/estore_tech/detail.aspx?ID=<%=GetProductID(1)%>"
><asp:image id="imgProduct1" runat="server"></asp:image></A><BR>
                  <asp:hyperlink id="Product1Description" Runat="server"></asp:hyperlink><BR>
            </TD>
            <TD vAlign="top" align="center" width="30%"><A
href="http://servername/estore_tech/detail.aspx?ID=<%=GetProductID(2)%>"
><asp:image id="imgProduct2" runat="server"></asp:image> </A>
                  <BR>
                  <asp:hyperlink id="Product2Description" runat="server"></asp:hyperlink><BR>
            </TD>
            <TD width="20%"></TD>
      </TR>
      <TR>
            <TD width="20%"></TD>
            <TD vAlign="top" align="center" width="30%"><A
href="http://servername/estore_tech/detail.aspx?ID=<%=GetProductID(3)%>"
><asp:image id="imgProduct3" runat="server"></asp:image> </A>
                  <BR>
                  <asp:hyperlink id="Product3Description" runat="server"></asp:hyperlink><BR>
            </TD>
            <BR>
            <TD vAlign="top" align="center" width="30%"><A
href="http://servername/estore_tech/detail.aspx?ID=<%=GetProductID(4)%>"
><asp:image id="imgProduct4" runat="server"></asp:image> </A>
                  <BR>
                  <asp:hyperlink id="Product4Description" runat="server"></asp:hyperlink><BR>
            </TD>
            <TD width="20%"></TD>
      </TR>
</TABLE>
<P></P>
<asp:label id="lblMessage" runat="server"></asp:label>

peterdidow

ASKER

NOTE: When I step through ProcessCheckBoxes(), checkbox.check is always false....not sure why.

Bob Learned

That is too much code. Where is the check box column defined?

Bob

peterdidow

ASKER

here is the code that actually pertains to the datagrid/checkbox.

Private Sub dgProducts_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs) Handles dgProducts.ItemDataBound
Dim checkBox As System.Web.UI.WebControls.CheckBox
Dim key As String
Select Case e.Item.ItemType
Case ListItemType.Item, ListItemType.AlternatingItem
checkBox = CType(e.Item.Controls(0).FindControl("CompletedCheckBox"), System.Web.UI.WebControls.CheckBox)
If Not IsNothing(checkBox) Then
key = dgProducts.DataKeys(e.Item.ItemIndex).ToString()
If Not CompletedList.ContainsKey(key) Then
checkBox.Checked = False
Else
checkBox.Checked = CType(CompletedList(key), Boolean)
End If

End If
End Select
'key = dgProducts.DataKeys(e.Item.ItemIndex).ToString()
'If dgProducts.DataKeyField = CompletedList(key) Then
' 'check it true

'Else
' 'unchecked.

'End If

End Sub

Private Sub ProcessCheckBoxes()
Dim checkBox As New System.Web.UI.WebControls.CheckBox
Dim key As String
For Each item As DataGridItem In dgProducts.Items
Select Case item.ItemType
Case ListItemType.Item, ListItemType.AlternatingItem
checkBox = CType(item.Controls(0).FindControl("chkSelected"), System.Web.UI.WebControls.CheckBox)

If Not IsNothing(checkBox) Then
key = dgProducts.DataKeys(item.ItemIndex).ToString()
If checkBox.Checked = True And (CompletedList.ContainsKey(key) = False Or CType(CompletedList(key), Boolean) = False) Then
CompletedList(key) = True
ElseIf checkBox.Checked = False And CompletedList.ContainsKey(key) = True And CType(CompletedList(key), Boolean) = True Then
CompletedList(key) = False
End If
End If

End Select

Next
End Sub
Private ReadOnly Property CompletedList() As Hashtable
Get
Dim hashtable As hashtable
If IsNothing(ViewState("Completed")) Then
hashtable = New hashtable
ViewState("Completed") = hashtable
Else
hashtable = CType(ViewState("Completed"), hashtable)
End If
Return hashtable
End Get
End Property

Public Sub BindData(ByVal val As Integer)
'Get the First Level Children for the selected Landing Page Category
Dim CategoryMGR As New BusinessRule.CCategories
Dim products As New FeaturedProducts.NFeaturedProduct
Dim c As New CXMLCategoryList
Dim oCatArray As ArrayList
Dim x As Integer
Dim oArray As ArrayList

oCatArray = CategoryMGR.GetFirstLevelChildren(ddlCategory.SelectedValue)
'Get Products by Category for each of the child categories

For x = 0 To oCatArray.Count - 1
c = oCatArray(x)
oArray = CategoryMGR.GetAllProductsByCategory(c.ID) 'the productid is returned.
Next

'the uid in the product table is the productid from above
' We need to grab the product data for each item in the arraylist (each product)

'GetProductData
dgProducts.CurrentPageIndex = val
If Not Page.IsPostBack Then
Dim ds As New DataSet
ds = products.LoadProductsForCategories(oArray)

dgProducts.DataKeyField = "UID"
dgProducts.DataSource = ds.Tables(0).DefaultView
Session("DS") = ds
dgProducts.DataBind()
Else
If Not Session("DS") Is Nothing Then
dgProducts.DataSource = Session("DS")
dgProducts.DataBind()
Else

Dim ds As New DataSet
ds = products.LoadProductsForCategories(oArray)

dgProducts.DataKeyField = "UID"
dgProducts.DataSource = ds.Tables(0).DefaultView
Session("DS") = ds
dgProducts.DataBind()
End If

End If

End Sub

Public Sub NewPage(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataGridPageChangedEventArgs) Handles dgProducts.PageIndexChanged

ProcessCheckBoxes()
BindData(e.NewPageIndex)
dgProducts.CurrentPageIndex = e.NewPageIndex

End Sub

Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click

Dim sb As StringBuilder = New StringBuilder
ProcessCheckBoxes()
sb.Append("<table>")
sb.Append("<tr><th>Order Checked</th></tr>")
For Each entry As DictionaryEntry In CompletedList
If CType(entry.Value, Boolean) = True Then
sb.AppendFormat("<tr><td>{0}</td></tr>", entry.Key)
End If
Next
sb.Append("</table>")
literal1.Text = sb.ToString()

'check if more than 4 have been Selected

Dim nCount As Integer
For Each dgItem As DataGridItem In dgProducts.Items
CheckBox = CType(dgItem.FindControl("chkSelected"), CheckBox)
If CheckBox.Checked = True Then
nCount += 1
End If
If nCount >= 4 Then
lblMessage.Text = "You may only select 4 items to be featured"
Exit Sub

End If

Next
nCount = 0
'Update the featured items for the selected toplevel category
Dim products As New FeaturedProducts.NFeaturedProduct
Dim oFeaturedProduct As New SystemBase.NFeaturedProductBase

For Each dgItem As DataGridItem In dgProducts.Items
CheckBox = CType(dgItem.FindControl("chkSelected"), CheckBox)
If CheckBox.Checked = True Then
nCount += 1
If nCount <= 4 Then
Dim FeaturedProductMGR As New BusinessRule.FeaturedProducts.NFeaturedProduct

Dim oFeaturedItem As New SystemBase.NFeaturedProductBase
oFeaturedItem.CategoryID = ddlCategory.SelectedValue
oFeaturedItem.FeaturedProductNumber = nCount
oFeaturedItem.ImageSmallPath = CType(dgItem.Cells(5).Text, String)
oFeaturedItem.Name = CType(dgItem.Cells(1).Text, String)
oFeaturedItem.UID = CType(dgItem.Cells(0).Text, Integer)
FeaturedProductMGR.SaveFeaturedProducts(oFeaturedItem)
End If

End If

Next

End Sub

ASKER CERTIFIED SOLUTION

Bob Learned

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