using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var result1 = new VerificationResult(false, new ErrorInfo("error", 0));

        var result2 = new VerificationResult(false, new ErrorInfo("error", 0));

        bool isEqual = result1.Equals(result2);

        bool contains = new List<VerificationResult> { result1 }.Contains(result2);

        Console.WriteLine(isEqual);

        Console.WriteLine(contains);

        var error1 = new ErrorInfo("error", 0);

        var error2 = new ErrorInfo("error", 0);

        bool isEqual2 = error1.Equals(error2);

        Console.WriteLine(isEqual2);

        bool isEqual3 = VerificationResult.Success().Equals(VerificationResult.Success());

        Console.WriteLine(isEqual3);

        var result3 = new VerificationResult(false, new ErrorInfo("error", 0));

        var result4 = result3 as VerificationResultEx;

        try {

            var result5 = (VerificationResultEx)result3;

​

            Console.WriteLine(result4);

        } catch (Exception e) {

            Console.WriteLine(e.Message);

        }

        Console.WriteLine(result5);

​

        var result6 = new VerificationResultEx(true, new ErrorInfo(), "success");

        var result7 = result6 as VerificationResult;

        bool isEqual4 = result6.Equals(result7);

        Console.WriteLine(isEqual4);

        var typeName = result1.GetType().Name;

        var result8 = (VerificationResultEx)result7;

        var info = result8.AdditionalInfo;

​

    }

}

​

public class VerificationResult : IDisposable {

        public VerificationResult(bool isValid, ErrorInfo errorInfo) {

            ErrorInfo = errorInfo;

            IsValid = isValid;

        }

​

        public bool IsValid { get; private set; }

        public ErrorInfo ErrorInfo { get; private set; }

​

        public static VerificationResult Success() {

            return new VerificationResult(true, new ErrorInfo());

        }

​

        public static VerificationResult Fail(ErrorInfo errorInfo) {

            return new VerificationResult(false, errorInfo);

        }

​

        public static VerificationResult Fail(string errorMessage, int errorCode) {

            return new VerificationResult(false, new ErrorInfo(errorMessage, errorCode));

        }

​

        public void Dispose() {

            Console.WriteLine("Dispose");

        }

​

        public virtual void A() {

            Console.WriteLine("A1");

        }

​

        public void B() {

            Console.WriteLine("B1");

        }

    }

​

    public struct ErrorInfo {

        public int Code { get; private set; }

        public string Message { get; private set; }

​

        public ErrorInfo(string message, int code): this() {

            Code = code;

            Message = message;

        }

    }

​

    public class VerificationResultEx : VerificationResult {

        public VerificationResultEx(bool isValid, ErrorInfo errorInfo, string additionalInfo):  

            base(isValid, errorInfo) {

            AdditionalInfo = additionalInfo;

        }

​

        public VerificationResultEx(bool isValid, ErrorInfo errorInfo)

            : base(isValid, errorInfo) {

            AdditionalInfo = null;

        }

​

        public string AdditionalInfo { get; private set; }

​

        public override void A() {

            Console.WriteLine("A2");

        }

​

        public new void B() {

            Console.WriteLine("B2");

        }

    }

​