TabStrip, Listview & Paging

[Roger]

I have a relatively simple page that contains a tagstrip, and depending on what tab is clicked I want to bind a listview for that appropriate pictures, including paging on the listview, this seems to work fine except for paging on the listview.

When I click to go to the next page, the need datasource is executed twice the first time my viewstate variable is nothing, even though it's been set when I click the tab, the second time it is something and the listview is bound, but the paging doesn't change.

I was getting a javascript serialization error earlier but it's went away for now.

Any ideas?

Aspx
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
    <telerik:RadTabStrip ID="RadTabStripSpecies" runat="server" MultiPageID="RadMultiPage1">
    </telerik:RadTabStrip>
    <div class="DesignWidth">
        <telerik:RadListView runat="server" ID="RadListViewPictures" AllowPaging="True" DataKeyNames="p_PictureID"
            EnableViewState="False">
            <ItemTemplate>
                <div class="rlvI" style="padding: 0px; margin: 5px; border: 10px ridge #C0C0C0; overflow: hidden;">
                    <img alt='<%# Eval("p_ImageFileName") %>' src='<%# Eval("p_ImageFileName","SquareThumbnail.ashx?p={0}") %>'
                        border="0" />
                </div>
            </ItemTemplate>
            <EmptyDataTemplate>
                <div class="RadListView RadListView_<%# Container.Skin %>">
                    <div class="rlvEmpty">
                        There are no items to be displayed.</div>
                </div>
            </EmptyDataTemplate>
            <LayoutTemplate>
                <div class="RadListView RadListViewFloated RadListView_<%# Container.Skin %>">
                    <div class="rlvFloated rlvAutoScroll">
                        <div id="itemPlaceholder" runat="server">
                        </div>
                    </div>
                    <telerik:RadDataPager ID="RadDataPager1" runat="server" PageSize="18" EnableViewState="False">
                        <Fields>
                            <telerik:RadDataPagerTemplatePageField>
                                <PagerTemplate>
                                </PagerTemplate>
                            </telerik:RadDataPagerTemplatePageField>
                            <telerik:RadDataPagerButtonField FieldType="FirstPrev" FirstButtonText="first" NextButtonText="next"
                                PrevButtonText="previous" LastButtonText="last" />
                            <telerik:RadDataPagerSliderField />
                            <telerik:RadDataPagerButtonField FieldType="NextLast" PrevButtonText="previous" LastButtonText="last"
                                NextButtonText="next" FirstButtonText="first" />
                            <telerik:RadDataPagerTemplatePageField>
                                <PagerTemplate>
                                </PagerTemplate>
                            </telerik:RadDataPagerTemplatePageField>
                        </Fields>
                    </telerik:RadDataPager>
                </div>
            </LayoutTemplate>
        </telerik:RadListView>
    </div>
</asp:Content>

Codebehind
 Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then
            Me.BindRadTabStripSpecies()
        End If
    End Sub

    Private Sub BindRadTabStripSpecies()
        Dim dt As New DataTable

        Try
            dt = Me.objDataAccess_Species.GetSpecies_Pictures
        Catch ex As Exception
            Me.SystemMessage("Error", "Data Retrieve Failed!", ex.Message)
            Exit Sub
        End Try

        Me.RadTabStripSpecies.CausesValidation = False
        Me.RadTabStripSpecies.DataTextField = "Name"
        Me.RadTabStripSpecies.DataNavigateUrlField = ""
        Me.RadTabStripSpecies.DataFieldID = "s_SpeciesID"
        Me.RadTabStripSpecies.DataValueField = "s_SpeciesID"
        Me.RadTabStripSpecies.DataFieldParentID = "sg_ParentSpeciesGroupID"
        Me.RadTabStripSpecies.DataSource = dt
        Me.RadTabStripSpecies.DataBind()
    End Sub

    Private Sub RadTabStripSpecies_TabClick(ByVal sender As Object, ByVal e As Telerik.Web.UI.RadTabStripEventArgs) Handles RadTabStripSpecies.TabClick
        e.Tab.Selected = True
        ViewState("Selects_SpeciesID") = CType(Me.RadTabStripSpecies.SelectedTab.Value, Integer)
        Me.RadListViewPictures.Rebind()
    End Sub

    Private Sub RadListViewPictures_NeedDataSource(ByVal sender As Object, ByVal e As Telerik.Web.UI.RadListViewNeedDataSourceEventArgs) Handles RadListViewPictures.NeedDataSource
        If IsNothing(ViewState("Selects_SpeciesID")) Then
            Exit Sub
        End If

        Dim s_SpeciesID As Integer = CType(ViewState("Selects_SpeciesID"), Integer)

        Dim dt As New DataTable

        Try
            dt = Me.objDataAccess_Picture.GetPicture_p_SpeciesID(s_SpeciesID)
        Catch ex As Exception
            Me.SystemMessage("Error", "Data Retrieve Failed!", ex.Message)
            Exit Sub
        End Try

        Dim Pictures As String = System.Configuration.ConfigurationManager.AppSettings("Pictures")
        Dim PicturesThumbs As String = System.Configuration.ConfigurationManager.AppSettings("PicturesThumbs")

        'Add a couple computed columns concatenating our Picture key value
        'dt.Columns.Add("ImageThumbURL", GetType(String), String.Format("'{0}' + {1}", PicturesThumbs, "p_ImageFileName"))
        'dt.Columns.Add("ImageURL", GetType(String), String.Format("'{0}' + {1}", Pictures, "p_ImageFileName"))

        Me.RadListViewPictures.DataSource = dt
    End Sub

[Roger]

If I change my variable to Session("Selects_SpeciesID") paging works, however, when I click to change tabs, it rebinds the listview for the old id then binds for my new tab id.

The NeedDatasource is executing before the tabclick event.

It works, but there's a significant amount of extra un-needed IO on the DB.

[Tsvetoslav]

Hello Roger,

You should switch ViewState for the RadListView and RadDataPager back on.

Hope it helps.

Best wishes,
Tsvetoslav
the Telerik team