$('#ProvinceId').change(function () {
            $('#DistrictId').attr('disabled', true);
            $('#dispreloader').fadeIn(200);
            $.getJSON('@Url.Action("GetDistricts/")' + $('#ProvinceId').val(), function (data) {
                var items = "";
                items += "<option value='' disabled selected>Seçim Yapın..</option>";
                $.each(data, function (i, item) {
                    items += "<option value='" + item.Id + "'>" + (item.Name) + "</option>";
                });
                $("#DistrictId").html(items);
                $('#DistrictId').removeAttr('disabled');
                $('#dispreloader').fadeOut(200);
            });
        });

public ActionResult GetDistricts(int Id)
        {
#if DEBUG
            System.Threading.Thread.Sleep(2000);
#endif
            return Json(DbContext.Districts.Where(p => p.ProvinceId == Id).Select(p => new { Id = p.Id, Name = p.Name }), JsonRequestBehavior.AllowGet);
        }