This is a special paging mode of jqGrid where standard paging is disabled and you can request new pages by scrolling the scrollbar to the bottom. This is very convenient for getting large amounts of data page by page while keeping the interface simple.

In order to use this mode, just set the PagerSettings.ScrollBarPaging to true. PagerSettings.PageSize is still active (controls the amount of rows retrieved).

You can see the this is optimized for performance - we can page with scrollbar 500,000 records with fast response times.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Trirand.Web.Mvc;
using System.Web.UI.WebControls;

namespace JQGridMVCExamples.Models
{
    public class OrdersJqGridModel
    {
        public JQGrid OrdersGrid { get; set; }

        public OrdersJqGridModel()
        {            
            OrdersGrid = new JQGrid
                             {
                                 Columns = new List()
                                 {
                                     new JQGridColumn { DataField = "OrderID", 
                                                        // always set PrimaryKey for Add,Edit,Delete operations
                                                        // if not set, the first column will be assumed as primary key
                                                        PrimaryKey = true,
                                                        Editable = false,
                                                        Width = 50 },                                    
                                     new JQGridColumn { DataField = "CustomerID", 
                                                        Editable = true,
                                                        Width = 100 },
                                     new JQGridColumn { DataField = "OrderDate",                                                         
                                                        Editable = true,
                                                        Width = 100, 
                                                        DataFormatString = "{0:yyyy/MM/dd}" },
                                     new JQGridColumn { DataField = "Freight", 
                                                        Editable = true,
                                                        Width = 75 },
                                     new JQGridColumn { DataField = "ShipName",
                                                        Editable =  true
                                                      }                                     
                                 },
                                 Width = Unit.Pixel(640),
                                 Height = Unit.Percentage(100)
                             };

            OrdersGrid.ToolBarSettings.ShowRefreshButton = true;            
        }
        
    }
}
<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<JQGridMVCExamples.Models.OrdersJqGridModel>" %>
<%@ Import Namespace="Trirand.Web.Mvc" %>
<%@ Import Namespace="JQGridMVCExamples.Models" %>

<!DOCTYPE html>
<html lang="en-us">
<head id="Head1" runat="server">
    <meta charset="utf-8">
    <title>jqGrid for ASP.NET MVC - Virtual Scrolling - Scrolling with ScrollBar</title>    
    <!-- The jQuery UI theme that will be used by the grid -->
    <link rel="stylesheet" type="text/css" href="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.10.3/themes/redmond/jquery-ui.css" />
    <!-- The jQuery UI theme extension jqGrid needs -->    
    <link rel="stylesheet" type="text/css" href="http://www.trirand.net/aspnetmvc/Content/themes/ui.jqgrid.css" />
    <!-- jQuery runtime minified -->
    <script src="http://ajax.microsoft.com/ajax/jquery/jquery-2.0.3.min.js" type="text/javascript"></script>
    <!-- The localization file we need, English in this case -->
    <script type="text/javascript" src="http://www.trirand.net/aspnetmvc/Scripts/trirand/i18n/grid.locale-en.js"></script>
    <!-- The jqGrid client-side javascript -->
    <script type="text/javascript" src="http://www.trirand.net/aspnetmvc/Scripts/trirand/jquery.jqGrid.min.js"></script>
    
    <!-- Refereces to the javascript client-side code of the jqDatePicker and jqAutoComplete controls to be used for editing -->
    <script type="text/javascript" src="http://www.trirand.net/aspnetmvc/Scripts/trirand/jquery.jqDatePicker.min.js"></script>    
    <script type="text/javascript" src="http://www.trirand.net/aspnetmvc/Scripts/trirand/jquery.jqAutoComplete.min.js"></script>  
</head>   

<body>
    <div>           
        <%= Html.Trirand().JQGrid(Model.OrdersGrid, "JQGrid1") %>
    </div>
    <br /><br />
    <div>
        <% Html.RenderPartial("CodeTabs"); %>        
    </div>
    
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Ajax;
using JQGridMVCExamples.Models;
using Trirand.Web.Mvc;
using System.Web.UI.WebControls;

namespace JQGridMVCExamples.Controllers.Grid
{
    public partial class GridController : Controller
    {
        // This is the default action for the View. Use it to setup your grid Model.
        public ActionResult PerformanceVirtualScrolling()
        {
            // Get the model (setup) of the grid defined in the /Models folder.
            var gridModel = new OrdersJqGridModel();

            // Customize/change some of the default settings for this model
            // ID is a mandatory field. Must by unique if you have several grids on one page.
            gridModel.OrdersGrid.ID = "OrdersGrid";
            // Setting the DataUrl to an action (method) in the controller is required.
            // This action will return the data needed by the grid
            gridModel.OrdersGrid.DataUrl = Url.Action("VirtualScrollingDataRequested");

            SetUpVirtualScrollingGrid(gridModel.OrdersGrid);

            // Pass the custmomized grid model to the View
            return View(gridModel);
        }

        // This method is called when the grid requests data. You can choose any method to call
        // by setting the JQGrid.DataUrl property
        public JsonResult VirtualScrollingDataRequested()
        {
            // Get both the grid Model and the data Model
            // The data model in our case is an autogenerated linq2sql database based on Northwind.
            var gridModel = new OrdersJqGridModel();
            var northWindModel = new NorthwindDataContext();

            SetUpVirtualScrollingGrid(gridModel.OrdersGrid);

            // return the result of the DataBind method, passing the datasource as a parameter
            // jqGrid for ASP.NET MVC automatically takes care of paging, sorting, filtering/searching, etc
            // Take first 500,000 rows.
            var result = from order in northWindModel.OrdersLarges
                         where order.OrderID <= 500000
                         select order;
                         
            return gridModel.OrdersGrid.DataBind(result);
        }

        private void SetUpVirtualScrollingGrid(JQGrid grid)
        {
            grid.PagerSettings.ScrollBarPaging = true;
            grid.PagerSettings.PageSize = 100;
            grid.Height = Unit.Pixel(300);            
        }
    }
}
Switch theme:


Theming is based on the very popular jQuery ThemeRoller standard. This is the same theming mechanism used by jQuery UI and is now a de-facto standard for jQuery based components. The benefits of using ThemeRoller are huge. We can offer a big set of ready to use themes created by professional designers, including Windows-like themes (Redmond), Apple-like theme (Cupertino), etc. In addition to that any jQuery UI controls on the same page will pick the same theme.

Last, but not least, you can always roll your own ThemeRoller theme, using the superb Theme Editor

To use a theme, simply reference 2 Css files in your Html <head> section - the ThemeRoller theme you wish to use, and the jqGrid own ThemeRoller Css file. For example (Redmond theme):

<link rel="stylesheet" type="text/css" media="screen" href="/themes/redmond/jquery-ui-1.8.2.custom.css" />
<link rel="stylesheet" type="text/css" media="screen" href="/themes/ui.jqgrid.css" />