<form> tag
with the
runat="server" attribute specified). Finally, we need
a series of
LinkButton Web controls, to display our Prev/First Page and Next/Last
Page links.
The content for the HTML section is as follows:
<html>
<body>
'For our recordcount and pagecount
<asp:Label id="lblPageCount" runat="server" /><br>
<asp:label id="RecordCount" runat="server" />
<form runat="server">
<ASP:Datagrid id="pubs" runat="server"
AllowPaging="True"
AllowCustomPaging="False"
Pagesize="10"
PagerStyle-Visible
= "False"
/>
<%-- Display the First Page/Previous Page buttons --%>
<asp:linkbutton id="Firstbutton" Text="<< 1st Page"
CommandArgument="0" runat="server"
onClick="PagerButtonClick"/>
<asp:linkbutton id="Prevbutton" Text= ""
CommandArgument="prev" runat="server"
onClick="PagerButtonClick"/>
<%-- Display the Next Page/Last Page buttons --%>
<asp:linkbutton id="Nextbutton" Text= ""
CommandArgument="next" runat="server"
onClick="PagerButtonClick"/>
<asp:linkbutton id="Lastbutton" Text="Last Page >>"
CommandArgument="last" runat="server"
onClick="PagerButtonClick"/>
<br><br><br><br>
Change Pagesize
<asp:DropDownList id="ps" runat="server">
<asp:ListItem>4</asp:ListItem>
<asp:ListItem>5</asp:ListItem>
<asp:ListItem>7</asp:ListItem>
<asp:ListItem selected>10</asp:ListItem>
<asp:ListItem>12</asp:ListItem>
<asp:ListItem>15</asp:ListItem>
<asp:ListItem>22</asp:ListItem>
</asp:DropDownList>
<asp:button text="Change Pagesize" runat="server" OnClick="RePage"/>
</form>
</body>
</html>
Note that in our DataGrid Web control we set the PagerStyle'sVisible property
to False. This is because we are implementing our own paging solution, and
don't want to use the default paging style supported by the DataGrid Web
control. (For more information on paging database results using the DataGrid's
built-in functionality, be sure to read: Paging
Database Results in ASP.NET!)
Also note that the four LinkButton controls all specify the server-side subroutine
PagerButtonClick as the sub to be called when they are clicked; similarly,
the "Change Pagesize" button has the RePage subroutine defined
as its OnClick event handler.
The event handler for the four LinkButtons (PagerButtonClick) must display
the appropriate page of data, be it the next page, the previous page, the first
page, or the last page. Which page to display, of course, depends on what LinkButton
the user clicked. The PagerButtonClick (shown below) uses the CommandArgument passed in from the LinkButton Web controls to determine which control was clicked,
and then takes the appropriate action.
Sub PagerButtonClick(sender As Object, e As EventArgs)
'used by external paging UI
Dim arg As String = sender.CommandArgument
Select arg
Case "next": 'The next Button was Clicked
If (Pubs.CurrentPageIndex < (Pubs.PageCount -
1)) Then
Pubs.CurrentPageIndex += 1
End If
Case "prev": 'The prev button was clicked
If (Pubs.CurrentPageIndex > 0) Then
Pubs.CurrentPageIndex -= 1
End If
Case "last": 'The Last Page button was clicked
Pubs.CurrentPageIndex = (Pubs.PageCount - 1)
Case Else: 'The First Page button was clicked
Pubs.CurrentPageIndex = Convert.ToInt32(arg)
End Select
'Now, bind the data!
BindSQL()
End Sub
The RePage event handler, which is called when the "Change Pagesize" button
is clicked, simply resets the DataGrid's CurrentPageIndex property back to
0 and rebinds the database data:
Sub Repage(sender As Object, e As EventArgs)
Pubs.CurrentPageIndex = 0
BindSQL()
End Sub
Finally, the last two server-side subroutines are two meager helper subroutines,
Next_Buttons() and Prev_Buttons(), which display the correct text for each
of the LinkButtons. These two subs, which are called from BindSQL(), can
be seen below:
Sub Prev_Buttons()
Dim PrevSet As String
If Pubs.CurrentPageIndex+1 <> 1 and ResultCount <> -1 Then
PrevSet = Pubs.PageSize
PrevButton.Text = ("< Prev " & PrevSet)
If Pubs.CurrentPageIndex+1 = Pubs.PageCount Then
FirstButton.Text = ("<< 1st Page")
End If
End If
End Sub
Sub Next_Buttons()
Dim NextSet As String
If Pubs.CurrentPageIndex+1 < Pubs.PageCount Then
NextSet = Pubs.PageSize
NextButton.Text = ("Next " & NextSet & " >")
End If
If Pubs.CurrentPageIndex+1 = Pubs.PageCount-1 Then
Dim EndCount As Integer
EndCount = ResultCount - (Pubs.PageSize * (Pubs.CurrentPageIndex+1))
NextButton.Text = ("Next " & EndCount & " >")
End If
End Sub
Well, that's it! Be sure to view the complete code (on the next page), try out the live demo, and read up on the related articles! If you have any questions, please do not hesitate to email me!
Happy Programming!
This article was originally published on 4guysfromrolla.com.
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