SF Events Filter code-behind 2

using System;
using System.Linq;
using System.Web.UI;
using Telerik.Sitefinity.Events.Model;
using Telerik.Sitefinity.GenericContent.Model;
using Telerik.Sitefinity.Modules.Events;
using Telerik.Sitefinity.Taxonomies;

namespace SitefinityWebApp.CustomWidgets
{
    public partial class CustomFilter : System.Web.UI.UserControl
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                TaxonomyManager taxMan = TaxonomyManager.GetManager();
                var categories = taxMan.GetTaxonomy(TaxonomyManager.CategoriesTaxonomyId).Taxa;
                categorySelector.DataValueField = "Id";
                categorySelector.DataTextField = "Title";
                categorySelector.DataSource = categories;
                categorySelector.DataBind();

                EventsManager eventsMan = EventsManager.GetManager();
                var cities = eventsMan.GetEvents().Select(evt => evt.City.ToString()).ToList().Distinct();
                citySelector.DataSource = cities;
                citySelector.DataBind();

            }
            Submit.Click += Submit_Click;
            Page.ViewStateMode = ViewStateMode.Enabled;
            Page.EnableViewState = true;
        }

        void Submit_Click(object sender, EventArgs e)
        {
            EventsManager eventsMan = EventsManager.GetManager();

            int? totalcount = -1;
            var categoryId = categorySelector.Items[categorySelector.SelectedIndex].Value;
            string city = citySelector.Items[citySelector.SelectedIndex].Value;

            IQueryable<Event> events = null;

            if (!categoryId.IsNullOrWhitespace())
            {
                events = eventsMan.Provider.GetItemsByTaxon(
                    new Guid(categoryId),
                    false,
                    "Category",
                    typeof(Event),
                    "Status = Master", "",
                    RadListView1.PageSize * RadListView1.CurrentPageIndex,
                    RadListView1.PageSize, ref totalcount).Cast<Event>().AsQueryable();
            }
            else
            {
                events = eventsMan.GetEvents()
                    .Where(evt => evt.Status == ContentLifecycleStatus.Master)
                    .Skip(RadListView1.PageSize * RadListView1.CurrentPageIndex)
                    .Take(RadListView1.PageSize);
            }

            if (!city.IsNullOrWhitespace())
                events = events.Where(evt => evt.City == city);

            if (RadDatePicker1.SelectedDate != null)
                events = events.Where(evt => evt.EventStart >= RadDatePicker1.SelectedDate);

            if(RadDatePicker2.SelectedDate != null)
                events = events.Where(evt => evt.EventStart <= RadDatePicker2.SelectedDate);

            RadListView1.DataSource = events;
            RadListView1.DataBind();
        }
    }
}