ASP.NetControls

ASP.Net - DataPager

The Data Pager control is used inside a listview object to setup a paging mechanism.

Here’s a sample of the code

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<asp:DataPager 
     ID = "DataPager_VendorAccount"
     runat = "server"
     PagedControlID="lvAccounts">
     <Fields>
          <asp:NextPreviousPagerField 
              ButtonType = "Button"
              ShowFirstPageButton = "True"
              ShowNextPageButton="False" />
          <asp:NumericPagerField />
          <asp:NextPreviousPagerField 
              ButtonType = "Button"
              ShowLastPageButton = "True"
              ShowPreviousPageButton="False" />
      </Fields>
 </asp:DataPager>

Typically, I place the datapager control inside the layout template of the ListVIew control. This helps the format of the data pager to match the layout of the ListView.

Usually, I have a second control - a simple textbox called “txtPageSize”. I will initialize this with a value (like 10), and when it’s changed I update the pagesize parameter of the listview control.

Here’s an example of the text box

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<asp:TextBox
     ID = "txtPageSize"
     runat = "server"
     Columns = "3"
     Text = "20"
     OnTextChanged="txtPageSize__TextChanged" 
     AutoPostBack="True" />

When it is changed, it calls a routine ‘TxtPageSize__TextChanged”, here’s a sample of that routine.

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Public Sub txtPageSize__TextChanged( _
         ByVal sender As Object, _
         ByVal e As System.EventArgs) 'Handles txtPageSize.TextChanged

     Dim txtPageSize As TextBox _
         = lvAccounts.FindControl("txtPageSize")

     Dim DataPager_VendorAccount As DataPager _
         = lvAccounts.FindControl("DataPager_VendorAccount")

     If IsNumeric(txtPageSize.Text) Then
         DataPager_VendorAccount.PageSize = txtPageSize.Text
     End If

     If IsNumeric(txtPageSize.Text) Then
         DataPager_VendorAccount.PageSize = txtPageSize.Text
         SI.sys.ParmSetValue("VendorAccountList_Page_Size", txtPageSize.Text.ToString, BillPay.BO_Staff.Get_ID_byNtUserName(SI.sys.ntUserNameNoWG), 5)
     End If

 End Sub

I adjust the control, but also I save this value into a systems parameter table, and reload it when the form is reconstructed. I do that with a few lines in the ListView PreRender event. Here’s a sample

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Protected Sub lvAccounts_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles lvAccounts.PreRender
     '
     ' page size logic
     Dim txtPageSize As TextBox _
         = lvAccounts.FindControl("txtPageSize")
     Dim DataPager_VendorAccount As DataPager _
         = lvAccounts.FindControl("DataPager_VendorAccount")
     txtPageSize.Text = SI.sys.ParmGetValue("VendorAccountList_Page_Size", "10", BillPay.BO_Staff.Get_ID_byNtUserName(SI.sys.ntUserNameNoWG), 5)
     DataPager_VendorAccount.PageSize = txtPageSize.Text

In theory when someone set’s the page size textbox, it is repopulated when they navigate back to the form.