using System;

using System.Collections.Generic;

using System.Text;

using System.Linq;

using System.Xml.Serialization;

using System.Xml;

using System.Xml.Linq;

using System.IO;

using System.Data;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

using System.IO.Compression;

​

// https://stackoverflow.com/questions/50164139/access-dictionary-items-in-data-property-of-exception-class/50164278#50164278

​

    public static class Constants

    {

        public const string ExceptionMessageKey = "UI Error Message";

    }

​

    public class TestClass

    {

        public static void Test()

        {

            try

            {

                var ReasonCodeID = -1;

                Exception ex = new Exception("Datebase error");

                ex.Data.Add(Constants.ExceptionMessageKey, "Whoops! Something went wrong there. Please call (555)555-5555 " +

                    "and notify them something is wrong with the Encounter Reason: " + ReasonCodeID);

                throw ex;

            }

            catch (Exception ex)

            {

                string text = ex.Data[Constants.ExceptionMessageKey]?.ToString();

                // IDIctionary get accessor should return null when key is missing, rather than throw an exception:

                string text2 = ex.Data["wrong key"]?.ToString();

                Console.WriteLine(text);

                Console.WriteLine(text2);

            }

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Roslyn 2.0 Compiler; Environment version: " + Environment.Version);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Uncaught exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​