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Virtual scrolling and paging Scroll bar position

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Grid

This is a migrated thread and some comments may be shown as answers.

Antony asked on 09 Mar 2009, 02:48 PM

Hello.

I've implemented paging and it works great, however, when I use the scroll bar to change the page the scroll bar position always goes back to the second/third page position. Below is my OnCommand method that deals with changing the page.

    
            args.set_cancel(true);  
        
                    var commandArg = args.get_commandArgument();  
        
                    if(commandArg == 'Next')  
        
                        thisSession.Grid.Page += 1;  
        
                    else if(commandArg == 'Prev')  
        
                        thisSession.Grid.Page -= 1;  
        
                    if(thisSession.Grid.Page == 0) thisSession.Grid.Page = 1;  
        
                    thisSession.Grid.Page = sender.get_masterTableView().get_currentPageIndex() + 1;  
        
                    if(args.get_commandName() == "Sort")  
        
                    {  
        
                        thisSession.Grid.SortExpression = sender.get_masterTableView().get_sortExpressions();  
        
                        var tsContent = $find('<%=tsContent.ClientID %>');  
        
                        if(!tsContent) return;  
        
                    }  
        
                    var tsContent = $find('<%=tsContent.ClientID %>');  
        
                    if(!tsContent) return;  
        
                    var searchID = tsContent.get_selectedTab().get_value();  
        
                    //getSearch(searchID);  
        
                    var searchText = (thisSession.Grid.SearchText == null) ? '' : thisSession.Grid.SearchText;  
        
                    PAB3.GetSearch(searchID.substring(4),thisSession.Grid.Days,  
        
                    thisSession.Grid.Page,thisSession.Grid.PageSize,thisSession.Grid.SortExpression, thisSession.Grid.SearchType,searchText,  
        
                    updateGrid_Paging,function(e){alert(e.get_message());});

4 Answers, 1 is accepted

answered on 11 Mar 2009, 10:49 AM

Hi Antony,

When scrolling with the virtual scroll bar, RadGrid can use either standard postbacks or AJAX requests (when AJAX callbacks are enabled using RadAjaxManager, RadAjaxPanel, or MS UpdatePanel

To enable virtual scrolling for browsing large record sets,

Set the ClientSettings.Scrolling.AllowScroll and ClientSettings.Scrolling.EnableVirtualScrollPaging properties to True.
Set the AllowPaging and AllowCustomPaging properties to True. Set the VirtualItemCount property to the total number of records in the data source.
Bind the grid using the NeedDataSource event, and in the event handler, use the CurrentPageIndex property to determine which subset of the records to fetch

Find more information about virtual scrolling in the following links:
Virtual Scrolling-Demo
Virtual Scrolling-Help topic

I hope this helps.

Regards,

Pavlina

the Telerik team

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answered on 16 Mar 2009, 02:10 PM

virtualpaging.zip

Hi Antony,

Indeed you can use VirtualScrollPaging in combination with client-side databinding. I have attached a small application which demonstrates the functionality in question.

Best wishes,
Rosen
the Telerik team

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