asked on

GridView in UpdatePanel paging

Dear experts,

I have an UpdatePanel and a GridView within it. I have a problem with paging: when I press Next button, grdUsers_PageIndexChanging() is not called, so the page stays 1, and if previously I changed selection in ddlPageSize, now it goes back to the initial selection.
Also, if I am on the first page, the Previous button is not disabled, and pressing it causes Out Of Range error.
What am I doing wrong?
Thanks.

<asp:UpdatePanel ID="upnlUsers" runat="server" ChildrenAsTriggers="true" UpdateMode="Always" >
        <ContentTemplate>
     
            <div style="height:400px; width:1500px; overflow:auto;">

            <asp:GridView ID="grdUsers" runat="server" AllowPaging="True" ShowHeader="false" ShowFooter="true" 
                AutoGenerateColumns="false" CssClass="largegridview largegridview_td" 
                Width="1480px" Height="100%" PageSize="100" DataKeyNames="ID" EnableSortingAndPagingCallbacks="false" 
                    onpageindexchanging="grdUsers_PageIndexChanging" 
                    onrowdatabound="grdUsers_RowDataBound">
                    <AlternatingRowStyle CssClass="alternatingrowstyle" />
                    
                    <Columns>
                         <asp:TemplateField HeaderText="User Name" SortExpression="Name">
                            <ItemTemplate>
                                <asp:Label ID="lblName" runat="server" Text='<%# Eval("Name") %>'></asp:Label>
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField HeaderText="Last Name" SortExpression="LastName">
                            <ItemTemplate>
                                <asp:Label ID="lblLastName" runat="server" Text='<%# Eval("LastName") %>'></asp:Label>
                            </ItemTemplate>
                        </asp:TemplateField>                        
                        <asp:TemplateField HeaderText="First Name" SortExpression="FirstName">
                            <ItemTemplate>
                                <asp:Label ID="lblFirstName" runat="server" Text='<%# Eval("FirstName") %>'></asp:Label>
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField HeaderText="Email" SortExpression="Email">
                            <ItemTemplate>
                                <asp:Label ID="lblEmail" runat="server" Text='<%# Eval("Email") %>'></asp:Label>
                            </ItemTemplate>
                        </asp:TemplateField>                        
  
                    </Columns>

                    <PagerStyle CssClass="pagerstyle" />
                    <PagerTemplate>
                        <asp:Label ID="Label1" runat="server" Text="Show rows:" />
                        <asp:DropDownList ID="ddlPageSize" runat="server" AutoPostBack="true" 
                            OnSelectedIndexChanged="ddlPageSize_SelectedIndexChanged">
                            <asp:ListItem Value="20" />
                            <asp:ListItem Value="50" />
                            <asp:ListItem Value="100" />
                        </asp:DropDownList>
                        &nbsp;
                        Page 
                        <asp:TextBox ID="txtGoToPage" runat="server" AutoPostBack="true" 
                            OnTextChanged="GoToPage_TextChanged" CssClass="gotopage" />
                        of
                        <asp:Label ID="lblTotalNumberOfPages" runat="server" />
                        &nbsp;
                        <asp:Button ID="btnPrev" runat="server" CommandName="Page" 
                            ToolTip="Previous Page" CommandArgument="Prev" CssClass="previous" />
                        <asp:Button ID="btnNext" runat="server" CommandName="Page" ToolTip="Next Page" 
                            CommandArgument="Next" CssClass="next" />                  
                    </PagerTemplate>                      
                </asp:GridView>
            </div>
        </ContentTemplate>
    </asp:UpdatePanel>

Open in new window

Mlanda T

give this a try:

Protected Sub grdUsers_PageIndexChanging(...) Handles gvEvents.PageIndexChanging

gvEvents.PageIndex = e.NewPageIndex
LoadData() //you must reload the data and rebind the grdiview
gvEvents.DataBind()

AJAXPanel.Update() // The below line refreshes the update panel..

end sub

also check if the page is posting back at all when you click to move onto another page (maybe just put a breakpoint on the Page_Load method or something AND also on grdUsers_PageIndexChanging).

tantormedia

ASKER

Thank you for your answer.
But what is "LoadData()"? Other than that, I do everything like you wrote, but the problem is that this event handler is not called at all, as I wrote above.

Kaushal Arora

LoadData means you need to rebind your gridview with the data you are binding with.

tantormedia

ASKER

So as I said, I did what you said without success.

Kaushal Arora

You are giving CommandName="Next" or "Prev" so it will never call the PageINdexChanging event.

Refer to this article for the details about the custom paging as you are doing.

http://www.codeproject.com/KB/grid/GridView_pager.aspx

Hope it helps you.

Mlanda T

I'm not so sure KaushalArora. Microsoft says (http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.pagertemplate.aspx)

Typically, button controls are added to the pager template to perform the paging operations. The GridView control performs a paging operation when a button control with its CommandName property set to "Page" is clicked. The button's CommandArgument property determines the type of paging operation to perform. The following table lists the command argument values supported by the GridView control.

ASKER CERTIFIED SOLUTION

Kaushal Arora

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