ValidateDto

using System;
using System.Collections.Generic;
using System.Linq;

namespace ValidatorDekorator
{
    class Program
    {
        static void Main(string[] args)
        {
            var car = new Car();
            car.Brand = "";
            car.Model = "Series 5";
            car.Version = "F10";
            car.Power = 560;
            car.GetType()
                .GetProperties()
                .ToList()
                .ForEach(p => System.Console.WriteLine($"{p.Name} = {p.GetValue(car)}"));
            Console.WriteLine("Validation!");
            car.Validate();
            Console.WriteLine("Hello World!");
        }
    }

    public class Car : ValidateGridView
    {
        [NotEmpty("Brand is required!")] public string Brand { get; set; }
        public string Model { get; set; }
        [NotEmpty("Version is required!")] public string Version { get; set; }
        public int Power { get; set; }
        public int Torque { get; set; }
        public float Weight { get; set; }
        public float Length { get; set; }
    }

    [System.AttributeUsage(AttributeTargets.All, Inherited = false, AllowMultiple = true)]
    sealed class NotEmpty : Attribute
    {
        readonly string _errorDescription;

        public NotEmpty(string errorDescription) => _errorDescription = errorDescription;

        public string ErrorDescription
        {
            get { return _errorDescription; }
        }

        public bool IsValid(object value)
        {
            if (value == null)
                return false;

            var stringValue = value as string;
            if (stringValue != null)
                return stringValue.Trim().Length != 0;

            return true;
        }
    }

    public class ValidateGridView
    {
        public void Validate()
        {
            var properites = this.GetType().GetProperties();
            var attrs = properites.Select(p =>
                (property: p, atribute: p.GetCustomAttributes(false).OfType<NotEmpty>()));
            List<string> validationresultOutput = new List<string>();
            foreach (var attr in attrs)
            {
                var propValue = attr.property.GetValue(this);
                var validationresult =
                    attr.atribute.Select(a => a.IsValid(propValue) ? string.Empty : a.ErrorDescription);
                validationresultOutput.Add(
                    $"{attr.property.Name}: {string.Join(", ", validationresult.Where(a => !string.IsNullOrEmpty(a)))}");
            }

            validationresultOutput.ForEach(Console.WriteLine);
        }
    }
}