DataPager with QueryStringField causes full PostBack inside UpdatePanel

Question

I have a ListView with three DataPager associated to it, all inside an UpdatePanel.

The first DataPager is only to show the link to the previous page:

<asp:DataPager ID="dpPrev" runat="server" PagedControlID="lvExperiences" QueryStringField="page" PageSize="4">
  <Fields>
    <asp:NextPreviousPagerField ShowNextPageButton="false" ButtonCssClass="PagePrev" />
  </Fields>
</asp:DataPager>

The second one is for the regular sequency of pages:

<asp:DataPager ID="dpList" runat="server" PagedControlID="lvExperiences" QueryStringField="page" PageSize="4">
  <Fields>
    <asp:NumericPagerField ButtonType="Link" CurrentPageLabelCssClass="PageCurrent" />
  </Fields>
</asp:DataPager>

And the last one is for the link to the next page:

<asp:DataPager ID="dpNext" runat="server" PagedControlID="lvExperiences" QueryStringField="page" PageSize="4">
  <Fields>
    <asp:NextPreviousPagerField ShowPrevPageButton="false" ButtonCssClass="PagePrev" />
  </Fields>
</asp:DataPager>

I put that controls separately, so I can disable the prev/next link in code behind depending if we are in the first/last page :

Protected Sub lvExperiences_DataBound(ByVal sender As Object, ByVal e As System.EventArgs) Handles lvExperiences.DataBound
    Dim page As Integer = 1
    If Not Request("page") Is Nothing Then
        page = Integer.Parse(Request("page"))
    End If
    dpPrev.Visible = ((dpPrev.PageSize * page) > dpPrev.TotalRowCount And (page > 1))
    dpNext.Visible = ((dpNext.PageSize * page) < dpNext.TotalRowCount)
End Sub

It works perfectly, but, such the DataPager is changing the URL in order to add the ?page=X, it makes a full PostBack. If I remove the DataBound method and the QueryStringField attributes from the DataPagers the UpdatePanel do its job and refresh only the ListView.

Anybody knows a way to know the current page without using the QueryStringField attribute?

Thanks a lot of,

Answer 1

Try this:

Protected Sub lvExperiences_DataBound(ByVal sender As Object, ByVal e As System.EventArgs) Handles lvExperiences.DataBound
   dpPrev.Visible = dpPrev.StartRowIndex > 0
   dpNext.Visible = (dpNext.StartRowIndex + dpNext.PageSize) < dpNext.TotalRowCount
End Sub