Validator.cs

using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using ValTool = System.ComponentModel.DataAnnotations;

namespace Validation
{
    public class Validator
    {
        public List<ValidationResult> ValidationErrors { get; private set; }

        public Validator(object dataObject)
        {
            _dataObject = dataObject;
        }

        public bool IsValid()
        {
            ValidationErrors = new List<ValidationResult>();

            if (_dataObject == null)
                return false;

            var context = new ValidationContext(_dataObject, null, null);
            return ValTool.Validator.TryValidateObject(_dataObject, context, ValidationErrors, true);
        }

        private readonly object _dataObject;
    }
}