Expression<Func<string, bool>> f = s => s.Length < 5;

Expression<Func<string, bool>> filter = s => s.Length > 5 && s.Length < 45;

ParameterExpression parameterExpression = Expression.Parameter(typeof(string));
MemberExpression memberExpression = Expression.Property(parameterExpression, "Length");

ConstantExpression greaterThanConstantExpression = Expression.Constant(5);
BinaryExpression greaterThanComparison = Expression.GreaterThan(memberExpression, greaterThanConstantExpression);
var greaterThan = Expression.Lambda<Func<string, bool>>(greaterThanComparison, parameterExpression);

ConstantExpression lessThanConstantExpression = Expression.Constant(45);
BinaryExpression lessThanComparsion = Expression.LessThan(memberExpression, lessThanConstantExpression);
var lessThan = Expression.Lambda<Func<string, bool>>(lessThanComparsion, parameterExpression);

var param = Expression.Parameter(typeof(string), "x");
var body = Expression.AndAlso(
            Expression.Invoke(greaterThan, param),
            Expression.Invoke(lessThan, param)
        );
Expression<Func<string, bool>> filter = Expression.Lambda<Func<string, bool>>(body, param);

Expression<Func<string, bool>> filter = s => s.Length > 5 && s.Length < 45;

public class DynamicModel
{
    public string Name { get; set; }
    public string Comparison { get; set; }
    public object Data { get; set; }
}

public static class ComparisonConstant
{
    public const string LessThan = "LesThan";
    public const string LessThanEqual = "LesThanEqual";
    public const string GreaterThan = "GreaterThan";
    public const string GreaterThanEqual = "GreaterThanEqual";
    public const string Equal = "Equal";
    public const string NotEqual = "NotEqual";
}

public static IQueryable<TModel> DynamicFilter<TModel>(this IQueryable<TModel> iqueryable, IEnumerable<DynamicModel> dynamicModel)
{
    return iqueryable.Where(Filter<TModel>(dynamicModel));
}  

public static Expression<Func<TModel, bool>> Filter<TModel>(IEnumerable<DynamicModel> dynamicModel)
{
    Expression<Func<TModel, bool>> result = a => true;
    foreach (var item in dynamicModel)
    {
        ParameterExpression parameterExpression = Expression.Parameter(typeof(TModel));
        MemberExpression memberExpression = Expression.Property(parameterExpression, item.Name);
        ConstantExpression constantExpression = Expression.Constant(item.Data);
        BinaryExpression comparison = GetBinaryExpression(item.Comparison, memberExpression, constantExpression);
        var expression = Expression.Lambda<Func<TModel, bool>>(comparison, parameterExpression);
        var param = Expression.Parameter(typeof(TModel), "x");
        var body = Expression.AndAlso(
                    Expression.Invoke(result, param),
                    Expression.Invoke(expression, param)
                );
        result = Expression.Lambda<Func<TModel, bool>>(body, param);
    }
    return result;
}

private static BinaryExpression GetBinaryExpression(string comparison, MemberExpression memberExpression, ConstantExpression constantExpression)
{
    switch (comparison)
    {
        case ComparisonConstant.Equal:
            return Expression.Equal(memberExpression, constantExpression);
        case ComparisonConstant.LessThan:
            return Expression.LessThan(memberExpression, constantExpression);
        case ComparisonConstant.GreaterThan:
            return Expression.GreaterThan(memberExpression, constantExpression);
        case ComparisonConstant.NotEqual:
            return Expression.NotEqual(memberExpression, constantExpression);
        case ComparisonConstant.GreaterThanEqual:
            return Expression.GreaterThanOrEqual(memberExpression, constantExpression);
        case ComparisonConstant.LessThanEqual:
            return Expression.LessThanOrEqual(memberExpression, constantExpression);
        default:
            return null;
    }
}

[
   {
      "Name":"Title",
      "Comparison":"Equal",
      "Data":"Hi"
   },
   {
      "Name":"Id",
      "Comparison":"LesThanEqual",
      "Data": 100
   }
]

var categories = _dbContext.Categories
                         .DynamicFilter(filter)//filter => IEnumerable<DynamicModel>
                         .ToList();

namespace WpfRptTests.Model
{
  public class Product
  {
      public string Name { set; get; }
      public int Price { set; get; }
  }
}

<FlowDocument xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
            xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
            FlowDirection="RightToLeft" FontFamily="Tahoma"
            xmlns:xrd="clr-namespace:CodeReason.Reports.Document;assembly=CodeReason.Reports"
            PageHeight="29.7cm" PageWidth="21cm" ColumnWidth="21cm">  

</FlowDocument>

  <xrd:ReportProperties>
      <xrd:ReportProperties.ReportName>SimpleReport</xrd:ReportProperties.ReportName>
      <xrd:ReportProperties.ReportTitle>گزارش از محصولات</xrd:ReportProperties.ReportTitle>
  </xrd:ReportProperties>

    <xrd:SectionReportHeader PageHeaderHeight="2" Padding="10,10,10,0" FontSize="12">
      <Table CellSpacing="0">
          <Table.Columns>
              <TableColumn Width="*" />
              <TableColumn Width="*" />
          </Table.Columns>
          <TableRowGroup>
              <TableRow>
                  <TableCell>
                      <Paragraph>
                          <xrd:InlineContextValue PropertyName="ReportTitle" />
                      </Paragraph>
                  </TableCell>
                  <TableCell>
                      <Paragraph TextAlignment="Right">
                          <xrd:InlineDocumentValue PropertyName="PrintDate" Format="dd.MM.yyyy HH:mm:ss" />
                      </Paragraph>
                  </TableCell>
              </TableRow>
          </TableRowGroup>
      </Table>
  </xrd:SectionReportHeader>

  <xrd:SectionReportFooter PageFooterHeight="2" Padding="10,0,10,10" FontSize="12">
      <Table CellSpacing="0">
          <Table.Columns>
              <TableColumn Width="*" />
              <TableColumn Width="*" />
          </Table.Columns>
          <TableRowGroup>
              <TableRow>
                  <TableCell>
                      <Paragraph>
                          نام کاربر:
                          <xrd:InlineDocumentValue PropertyName="RptBy" Format="dd.MM.yyyy HH:mm:ss" />
                      </Paragraph>
                  </TableCell>
                  <TableCell>
                      <Paragraph TextAlignment="Right">
                          صفحه
                          <xrd:InlineContextValue PropertyName="PageNumber" FontWeight="Bold" /> از
                          <xrd:InlineContextValue PropertyName="PageCount" FontWeight="Bold" />
                      </Paragraph>
                  </TableCell>
              </TableRow>
          </TableRowGroup>
      </Table>
  </xrd:SectionReportFooter>

data.ReportDocumentValues.Add("PrintDate", DateTime.Now);
data.ReportDocumentValues.Add("RptBy", "وحید");

  <Section Padding="80,10,40,10" FontSize="12">
      <Paragraph FontSize="24" TextAlignment="Center" FontWeight="Bold">
          <xrd:InlineContextValue PropertyName="ReportTitle" />
      </Paragraph>
      <Paragraph  TextAlignment="Center">
          گزارش از لیست محصولات در تاریخ:
          <xrd:InlineDocumentValue PropertyName="PrintDate" Format="dd.MM.yyyy HH:mm:ss" />
          توسط:
          <xrd:InlineDocumentValue PropertyName="RptBy" Format="dd.MM.yyyy HH:mm:ss" />
      </Paragraph>
      <xrd:SectionDataGroup DataGroupName="ItemList">
          <Table CellSpacing="0" BorderBrush="Black" BorderThickness="0.02cm">
              <Table.Resources>
                  <!-- Style for header/footer rows. -->
                  <Style x:Key="headerFooterRowStyle" TargetType="{x:Type TableRowGroup}">
                      <Setter Property="FontWeight" Value="DemiBold"/>
                      <Setter Property="FontSize" Value="16"/>
                      <Setter Property="Background" Value="LightGray"/>
                  </Style>

                  <!-- Style for data rows. -->
                  <Style x:Key="dataRowStyle" TargetType="{x:Type TableRowGroup}">
                      <Setter Property="FontSize" Value="12"/>
                  </Style>

                  <!-- Style for data cells. -->
                  <Style TargetType="{x:Type TableCell}">
                      <Setter Property="Padding" Value="0.1cm"/>
                      <Setter Property="BorderBrush" Value="Black"/>
                      <Setter Property="BorderThickness" Value="0.01cm"/>
                  </Style>
              </Table.Resources>

              <Table.Columns>
                  <TableColumn Width="0.8*" />
                  <TableColumn Width="0.2*" />
              </Table.Columns>
              <TableRowGroup Style="{StaticResource headerFooterRowStyle}">
                  <TableRow>
                      <TableCell>
                          <Paragraph TextAlignment="Center">
                              <Bold>نام محصول</Bold>
                          </Paragraph>
                      </TableCell>
                      <TableCell>
                          <Paragraph TextAlignment="Center">
                              <Bold>قیمت</Bold>
                          </Paragraph>
                      </TableCell>
                  </TableRow>
              </TableRowGroup>

              <TableRowGroup Style="{StaticResource dataRowStyle}">
                  <xrd:TableRowForDataTable TableName="Product">
                      <TableCell>
                          <Paragraph>
                              <xrd:InlineTableCellValue PropertyName="Name" />
                          </Paragraph>
                      </TableCell>
                      <TableCell>
                          <Paragraph TextAlignment="Center">
                              <xrd:InlineTableCellValue PropertyName="Price" AggregateGroup="Group1" />
                          </Paragraph>
                      </TableCell>
                  </xrd:TableRowForDataTable>
              </TableRowGroup>

              <TableRowGroup Style="{StaticResource headerFooterRowStyle}">
                  <TableRow>
                      <TableCell>
                          <Paragraph TextAlignment="Right">
                              <Bold>جمع کل</Bold>
                          </Paragraph>
                      </TableCell>
                      <TableCell>
                          <Paragraph TextAlignment="Center">
                              <Bold>
                                  <xrd:InlineAggregateValue AggregateGroup="Group1"
                                                            AggregateValueType="Sum"
                                                            EmptyValue="0"
                                                            FontWeight="Bold" />
                              </Bold>
                          </Paragraph>
                      </TableCell>
                  </TableRow>
              </TableRowGroup>

          </Table>

          <Paragraph TextAlignment="Center" Margin="5">
              در این گزارش
              <xrd:InlineAggregateValue AggregateGroup="Group1"
                                        AggregateValueType="Count"
                                        EmptyValue="هیچ"
                                        FontWeight="Bold" /> محصول با جمع کل قیمت
              <xrd:InlineAggregateValue AggregateGroup="Group1"
                                        AggregateValueType="Sum"
                                        EmptyValue="0"
                                        FontWeight="Bold" /> وجود دارند.
          </Paragraph>
      </xrd:SectionDataGroup>
  </Section>

<Window x:Class="WpfRptTests.MainWindow"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:c="clr-namespace:CodeReason.Reports.Controls;assembly=CodeReason.Reports"
      xmlns:vm="clr-namespace:WpfRptTests.ViewModel"
      Title="MainWindow" WindowState="Maximized" Height="350" Width="525">
  <Window.Resources>
      <vm:ProductViewModel x:Key="vmProductViewModel" />
  </Window.Resources>
  <Grid DataContext="{Binding Source={StaticResource vmProductViewModel}}">
      <c:BusyDecorator IsBusyIndicatorHidden="{Binding RptGuiModel.IsBusyIndicatorHidden}">
          <DocumentViewer Document="{Binding RptGuiModel.Document}"  />
      </c:BusyDecorator>
  </Grid>
</Window>

using System.ComponentModel;
using System.Windows.Documents;

namespace WpfRptTests.Model
{
  public class RptGuiModel
  {
      public IDocumentPaginatorSource Document { get; set; }
      public bool IsBusyIndicatorHidden { get; set; }
  }
}

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading;
using CodeReason.Reports;
using WpfRptTests.Helper;
using WpfRptTests.Model;

namespace WpfRptTests.ViewModel
{
  public class ProductViewModel
  {
      #region Constructors (1)

      public ProductViewModel()
      {
          RptGuiModel = new RptGuiModel();
          if (Stat.IsInDesignMode) return;
          //انجام عملیات نمایش گزارش در یک ترد دیگر جهت قفل نشدن ترد اصلی برنامه
          showReportAsync();
      }

      #endregion Constructors

      #region Properties (1)

      public RptGuiModel RptGuiModel { set; get; }

      #endregion Properties

      #region Methods (3)

      // Private Methods (3)

      private static List<Product> getProducts()
      {
          var products = new List<Product>();
          for (var i = 0; i < 100; i++)
              products.Add(new Product { Name = string.Format("Product{0}", i), Price = i });

          return products;
      }

      private void showReport()
      {
          try
          {
              //Show BusyIndicator
              RptGuiModel.IsBusyIndicatorHidden = false;

              var reportDocument =
                  new ReportDocument
                  {
                      XamlData = File.ReadAllText(@"Report\SimpleReport.xaml"),
                      XamlImagePath = Path.Combine(Environment.CurrentDirectory, @"Report\")
                  };

              var data = new ReportData();

              // تعریف متغیرهای دلخواه و مقدار دهی آن‌ها
              data.ReportDocumentValues.Add("PrintDate", DateTime.Now);
              data.ReportDocumentValues.Add("RptBy", "وحید");

              // استفاده از یک سری اطلاعات آزمایشی به عنوان منبع داده
              data.DataTables.Add(getProducts().ToDataTable());

              var xps = reportDocument.CreateXpsDocument(data);
              //انقیاد آن به صورت غیر همزمان در ترد اصلی برنامه
              DispatcherHelper.DispatchAction(
                  () => RptGuiModel.Document = xps.GetFixedDocumentSequence()
                  );
          }
          catch (Exception ex)
          {
              //وجود این مورد ضروری است زیرا بروز استثناء در یک ترد به معنای خاتمه آنی برنامه است
              //todo: log errors
          }
          finally
          {
              //Hide BusyIndicator
              RptGuiModel.IsBusyIndicatorHidden = true;
          }
      }

      private void showReportAsync()
      {
          var thread = new Thread(showReport);
          thread.SetApartmentState(ApartmentState.STA); //for DocumentViewer
          thread.Start();
      }

      #endregion Methods
  }
}

 public class EnumObject
        {
            public Enum ValueMember { get; set; }
            public int intValueMember
            {
                get { return int.Parse(ValueMember.ToString("D")); }
            }
            public string stringValueMember
            {
                get { return ValueMember.ToString(""); }
            }
            public string DisplayMember
            {
                get { return ValueMember.GetDescription(); }
            }
        }

      public static List<EnumObject> GetEnumList(this Enum enu)
        {
            List<EnumObject> li = new List<EnumObject>();
            foreach (var item in enu.GetType().GetEnumValues())
            {
                li.Add(new EnumObject { ValueMember = (Enum)item });
            }
            return li;
        }

          comboBox1.DataSource = Grade.VeryGood.GetEnumList();
          comboBox1.DisplayMember = "DisplayMember";
          comboBox1.ValueMember = "ValueMember";

        public static List<EnumObject> EnumToList<T>()
        {
            Type enumType = typeof(T);
            if (enumType.BaseType != typeof(Enum))
                throw new ArgumentException("T must be of type System.Enum");

            List<EnumObject> li = new List<EnumObject>();
            foreach (var item in enumType.GetEnumValues())
            {
                li.Add(new EnumObject { ValueMember = (Enum)item });
            }
            return li;
        }

    comboBox1.DataSource =ExtensionMethodCls.EnumToList<Grade>();
          comboBox1.DisplayMember = "DisplayMember";
          comboBox1.ValueMember = "ValueMember";

 public static class ExtensionMethodCls
    {
        public class EnumObject
        {
            public Enum ValueMember { get; set; }
            public int intValueMember
            {
                get { return int.Parse(ValueMember.ToString("D")); }
            }
            public string stringValueMember
            {
                get { return ValueMember.ToString(""); }
            }
            public string DisplayMember
            {
                get { return ValueMember.GetDescription(); }
            }
        }
 
    

        public static List<EnumObject> EnumToList<T>()
        {
            Type enumType = typeof(T);
            if (enumType.BaseType != typeof(Enum))
                throw new ArgumentException("T must be of type System.Enum");

            List<EnumObject> li = new List<EnumObject>();
            foreach (var item in enumType.GetEnumValues())
            {
                li.Add(new EnumObject { ValueMember = (Enum)item });
            }
            return li;
        }

        public static List<EnumObject> GetEnumList(this Enum enu)
        {
            List<EnumObject> li = new List<EnumObject>();
            foreach (var item in enu.GetType().GetEnumValues())
            {
                li.Add(new EnumObject { ValueMember = (Enum)item });
            }
            return li;
        }

        public static string GetDescription(this Enum enu)
        {

            Type type = enu.GetType();

            MemberInfo[] memInfo = type.GetMember(enu.ToString());

            if (memInfo != null && memInfo.Length > 0)
            {

                object[] attrs = memInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);

                if (attrs != null && attrs.Length > 0)
                    return ((DescriptionAttribute)attrs[0]).Description;
            }

            return enu.ToString();

        }
    }

public string RedirectUrl {get; set; }

...
if(cache[hasValue] != null) {
      filterContext.Controller.ViewData.ModelState.AddModelError("...", ...);
      filterContext.HttpContext.Response.Redirect(RedirectUrl);
}

mysite.com/reporting

using System.ComponentModel.DataAnnotations;

namespace SampleProject.Models
{
    public class Channel
    {
        public string ChannelTitle { get; set; }
        [Required]
        public string ChannelUrl { get; set; }
    }
}

using System.Collections.Generic;

namespace SampleProject.Models
{
    public static class ChannelDataSource
    {
        static ChannelDataSource() => Channels = new List<Channel>();
        public static List<Channel> Channels { get; private set; }
        public static void Add(Channel channel) => Channels.Add(channel);
    }
}

using SampleProject.Models;
using System.Linq;
using System.Web.Mvc;

namespace SampleProject.Controllers
{
    public class ChannelController : Controller
    {
        // GET: Channel
        public ActionResult Index()
        {
            var channels = ChannelDataSource.Channels;
            return View(channels);
        }

        public ActionResult Channel(string channelUrl)
        {
            if (string.IsNullOrWhiteSpace(channelUrl))
            {
                return new HttpNotFoundResult("channel not found!");
            }
            var channel = ChannelDataSource.Channels.SingleOrDefault(ch => ch.ChannelUrl == channelUrl.ToLower());
            if (channel == null)
            {
                return new HttpNotFoundResult("channel not found!");
            }
            return View(channel);
        }

        public ActionResult Create() => View();

        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(Channel channel)
        {
            if (!ModelState.IsValid)
            {
                ModelState.AddModelError(string.Empty, "Please check your inputs!");
                return View(channel);
            }
            ChannelDataSource.Add(channel);
            TempData["Message"] = "Channel added successfully!";
            return RedirectToAction(nameof(Index));
        }
    }
}

using System.Web.Mvc;
using System.Web.Routing;

namespace SampleProject
{
    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                name: "ChannelUrls",
                url: "{channelurl}",
                defaults: new { controller = "Channel", action = "Channel", id = UrlParameter.Optional }
            );

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Channel", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

using System.Collections.Generic;
using System.Linq;
using System.Web.Routing;

namespace SampleProject.Models
{
    public static class Utility
    {
        public static List<string> GetAllAreaNames()
        {
            var areaNames = RouteTable.Routes.OfType<Route>()
                            .Where(d => d.DataTokens != null)
                            .Where(d=> d.DataTokens.ContainsKey("area"))
                            .Select(r => r.DataTokens["area"].ToString().ToLower())
                            .ToList();
            return areaNames;
        }
    }
}

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web.Mvc;
using SampleProject.Models;

namespace SampleProject.CustomValidators
{
    public class CheckForAreaExisting : ValidationAttribute, IClientValidatable
    {
        public List<string> AreaNames
        {
            get
            {
                return Utility.GetAllAreaNames();
            }
        }
        public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
        {
            var rule = new ModelClientValidationRule
            {
                ValidationType = "checkforareaexisting",
                ErrorMessage = FormatErrorMessage(metadata.GetDisplayName())
            };
            rule.ValidationParameters.Add("areanames", string.Join(",", AreaNames));
            yield return rule;
        }

        public override bool IsValid(object value)
        {
            if (value != null)
            {
                return Utility.GetAllAreaNames()
                   .SingleOrDefault(area => area == value.ToString().ToLower()) == null;
            }
            return true;
        }
    }
}

jQuery.validator.addMethod("checkforareaexisting",
    function (value, element, param) {
        var isValueOneOfTheAreaNames = $.inArray(value.toLowerCase(), param.areaNames) === -1;
        return isValueOneOfTheAreaNames;
    });

$.validator.unobtrusive.adapters.add('checkforareaexisting', ['areanames'], function (options) {
    options.rules['checkforareaexisting'] = { areaNames: options.params.areanames.split(',') };
    options.messages['checkforareaexisting'] = options.message;
});

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>_Layout</title>
    <style>

    </style>
</head>
<body>
    <div>
        @RenderBody()
    </div>
    <script src="~/Scripts/Jquery.js"></script>
    <script src="~/Scripts/jquery.validate.min.js"></script>
    <script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>
    <script src="~/Scripts/CustomValidation.js"></script>
</body>
</html>

using SampleProject.CustomValidators;
using System.ComponentModel.DataAnnotations;

namespace SampleProject.Models
{
    public class Channel
    {
        public string ChannelTitle { get; set; }
        [Required]
        [CheckForAreaExisting(ErrorMessage = "You can't use this url for your channel!")]
        public string ChannelUrl { get; set; }
    }
}

[HttpPost]
public ActionResult CheckForAreaExisting(string channelUrl)
{
    var isValueOneOfTheAreaNames = Utility.GetAllAreaNames()
                                   .SingleOrDefault(area => area == channelUrl.ToLower()) == null;
    return Json(isValueOneOfTheAreaNames);
}  

using System.ComponentModel.DataAnnotations;
using System.Web.Mvc;

namespace SampleProject.Models
{
    public class Channel
    {
        public string ChannelTitle { get; set; }
        [Required]
        [Remote("CheckForAreaExisting", "Channel",
            ErrorMessage = "You can't use this url for your channel!",
            HttpMethod = "Post")]
        public string ChannelUrl { get; set; }
    }
}