How to export current page/selected record in ASP.NET Web Forms Grid?

@(Html.EJ().Grid<object>("ExportingGrid")
      .Datasource((IEnumerable<OrdersView>)ViewBag.datasource)
      .EditSettings(edit => { edit.AllowAdding().AllowDeleting().AllowEditing(); })
      .ToolbarSettings(tool => tool.ShowToolbar().ToolbarItems(item =>
       {
           item.AddTool(ToolBarItems.ExcelExport);
           item.AddTool(ToolBarItems.PdfExport);
           item.AddTool(ToolBarItems.WordExport);
       }))
       .AllowPaging()
      .Columns(col =>
        {
            col.Field("OrderID").Add();
            col.Field("CustomerID").Add();
            col.Field("EmployeeID").Add();
            col.Field("Freight").Format("{0:C2}").Add();
        })
      .ClientSideEvents(evt => evt.ToolbarClick("OnToolbarClick"))
)

<script>
    function OnToolbarClick(args) {
        if (args.itemName.indexOf("Export") > -1) {//if no selectedRecords, currenviewdata will be exported
            this.model["currentData"] = JSON.stringify(this.model.selectedRecords.length == 0 ? this.model.currentViewData : this.model.selectedRecords);
        }
    }
</script>

namespace MvcApplication66.Controllers
{
    public class HomeController : Controller
    {
        public IEnumerable currentData;
        public ActionResult Index(){
            var data = new NorthwindDataContext().OrdersViews.ToList();
            ViewBag.datasource = data;
            return View();
        }
            //Likewise perform exporting for pdf and word
        public void ExportToExcel(string GridModel)
        {
            ExcelExport exp = new ExcelExport();
            GridProperties obj = ConvertGridObject(GridModel);
            exp.Export(obj, currentData, "Export.xlsx", ExcelVersion.Excel2010, false, false, "flat-saffron");
        }
        private GridProperties ConvertGridObject(string gridProperty)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            IEnumerable div = (IEnumerable)serializer.Deserialize(gridProperty, typeof(IEnumerable));
            GridProperties gridProp = new GridProperties();
            foreach (KeyValuePair<string, object> ds in div)
            {
                var property = gridProp.GetType().GetProperty(ds.Key, BindingFlags.Instance | BindingFlags.Public | BindingFlags.IgnoreCase);
 
                if (ds.Key == "currentData")
                {
                    string str = Convert.ToString(ds.Value);
                    currentData = JsonConvert.DeserializeObject<IEnumerable<OrdersView>>(str);
                    continue;
                }
 
                if (property != null)
                {
                    Type type = property.PropertyType;
                    string serialize = serializer.Serialize(ds.Value);
                    object value = serializer.Deserialize(serialize, type);
                    property.SetValue(gridProp, value, null);
                }
            }
            return gridProp;
        }
    }

    public partial class ExcelExporting : System.Web.UI.Page
    {
        public IEnumerable currentData;
        List<Orders> order = new List<Orders>();
        protected void Page_Load(object sender, EventArgs e)
        {
            BindDataSource();
        }
        [System.Web.Http.ActionName("ExcelExport")]
        [AcceptVerbs("POST")]
        public void ExcelExport()
        {
 
            string gridModel = HttpContext.Current.Request.Params["GridModel"];
 
            GridProperties gridPropert = ConvertGridObject(gridModel);
 
            ExcelExport exp = new ExcelExport();
 
            IEnumerable data = currentData;
 
            exp.Export(gridPropert, (IEnumerable)data, "Export.xlsx", ExcelVersion.Excel2010, false, false, "flat-azure-dark");
            //Likewise perform exporting for pdf and word
 
        }
        private GridProperties ConvertGridObject(string gridProperty)
        {
            JavaScriptSerializer serializer = new JavaScriptSerializer();
            IEnumerable div = (IEnumerable)serializer.Deserialize(gridProperty, typeof(IEnumerable));
            GridProperties gridProp = new GridProperties();
            foreach (KeyValuePair<string, object> ds in div)
            {
                var property = gridProp.GetType().GetProperty(ds.Key, BindingFlags.Instance | BindingFlags.Public | BindingFlags.IgnoreCase);
  
                //Check and retrieve additional property here
                if (ds.Key == "currentData")
                {
                    string str = Convert.ToString(ds.Value);
                    currentData = JsonConvert.DeserializeObject<IEnumerable<OrdersView>>(str);
                    continue;
                }
                if (property != null)
                {
                    Type type = property.PropertyType;
                    string serialize = serializer.Serialize(ds.Value);
                    object value = serializer.Deserialize(serialize, type);
                    property.SetValue(gridProp, value, null);
                }
            }
            return gridProp;
        }
}