Paging by example - help - still no luck....

14 Apr 2005 8:48 PM

Tmuld

Hello,

I was looking at the example provided on:
http://www.4guysfromrolla.com/webtech/072101-1.2.shtml
for paging.

I am using Visual Studio 2003 - Microsoft Development Environment 2003

For paging the page url mentions setting properties to be set as:

AllowPaging="True"
              PageSize="15"
              OnPageIndexChanged="dgPopularFAQs_Paged">

Ok. I am looking at my datagrid in the design view - there is a Allow
Paging, PageSize - but no OnPageIndexChanged!!

I went to the code behine - at the top selected my datagrid in the top
left drop down menu, and could not find OnPageIndexChanged in the
declarations menu. There is a 'PageIndexChanged' changed - is that it?

Well, I put this code in that area (using a Dataset called ds):

Private Sub dg_PageIndexChanged(ByVal source As Object, ByVal e As
System.Web.UI.WebControls.DataGridPageChangedEventArgs) Handles
dg.PageIndexChanged
        dg.CurrentPageIndex = e.NewPageIndex
        dg.DataBind()
    End Sub

The paging numbers show up on the grid, but when I hit any of the
numbers - the same screen shows up - 10 records, it does not advance
(set to 10 in the property builder). It never advances. In my page
load I have this:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
        If Not Page.IsPostBack Then

                     dgDataBind()
        End If
    End Sub

Any help?

Thanks,

Tmuld

15 Apr 2005 7:35 AM

Cor Ligthert

Tmuld,

Why don't you just use the samples on MSDN for paging a datagrid, they are
in my opinion very well.

One of them
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_vbcode/html/vbtskCodePagingInDataGridWebControlVisualBasic.asp

I hope this helps,

Cor

15 Apr 2005 1:45 PM

Tmuld

Thanks - it does work very well!

I still have some issues. I used the MSDN code and it sort of works.
Now the paging works, but when I hit the number - it does not show my
records until I hit the search button again. I thought it would go to
the next records automatically. Not sure why? Do I need to do some
sort of refresh at the button level?

[Plus I also do not understand this line:

dsQuery = CType(Session("dataset"), DataSet1).   I already have a
dataset defined at design time - what does this do? ]

Here is my code:
- my dataset is called 'ds'

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
                With dg
            .AllowPaging = True
            .PagerStyle.Mode = PagerMode.NumericPages
            .PageSize = 5
            .PagerStyle.PageButtonCount = 5
        End With
        If IsPostBack Then
            ds = CType(Session("dataset"), DataSet1)
        Else
            daQuery.Fill(ds)
            Session("dataset") = ds
            DataBind()
        End If
    End Sub

The button code->filters out data with a dataview. So after the page
button is pressed - one gets a blank screen untill the button is
pressed again - then it moves to the next results.

Private Sub btn_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles btn.Click
        Dim Count As Integer

        Dim dv As DataView = ds.Tables("DB").DefaultView
        dv.RowFilter = "Title like '%" & txt.Text & "%' OR Address like
'%" & txt.Text & "%'"
        Count = dv.Count
        dg.DataSource = dv
        dg.DataBind()
        lblCount.Text = Count

    End Sub

Paging:

Private Sub dg_PageIndexChanged(ByVal source As Object, ByVal e As
System.Web.UI.WebControls.DataGridPageChangedEventArgs) Handles
dg.PageIndexChanged
        dg.CurrentPageIndex = e.NewPageIndex
        dg.DataBind()
    End Sub

15 Apr 2005 2:07 PM

Cor Ligthert

Tmuld,

A webpage is not persistent, what means that with every send and get back
all the data on serverside is removed. For that are some solutions for with
is the session the most simple. The most simple because it can fit
automatically (serialized) the dataset.

Therefore you have to set that dataset again when there is a postback to the
session (and as well when you do a fill to renew it).

Your other question is what I am always struggling with as well, so take
some time to find that.

Cor