using System;

using System.Text;

using System.Threading.Tasks;

​

public class Program

{

    public static void Main()

    {

        // String

        String s = "Hi there.";

​

        // Encoding object

        Encoding encodingUTF8 = Encoding.UTF8;

​

        // Encode string to byte array

        Byte[] encodedBytes = encodingUTF8.GetBytes(s);

        Console.WriteLine("Encoded bytes: " +

                          BitConverter.ToString(encodedBytes));

​

        // Decode to string

        String decodedString = encodingUTF8.GetString(encodedBytes);

        decodedString = "ØMI";

        Console.WriteLine("Decoded string: " + decodedString);

        string a = string.Empty;

        Exception b = null;

        Console.WriteLine("b4");

        try

        {

            a = AAA().Result;

            //b = AAA().Exception;

            Console.WriteLine("ok a = " + a);

            Console.WriteLine("ok b = " + b);

        }

        catch (Exception e) 

        {

            Console.WriteLine("ex a = " + a);

            Console.WriteLine("ex b = " + b);

            //Console.WriteLine("out     " + e);

        }

        Console.WriteLine("at");

    }

    public static Task<string> AAA()

    {

        string a = null;

        TaskCompletionSource<string> tcs = new TaskCompletionSource<string>();

        try 

        {

            a.Split(',');

            tcs.SetResult("true");

        }

        catch (Exception e)

        {

            //throw e;

            Console.WriteLine("eeeee");

            tcs.SetException(new Exception("11111"));

            Console.WriteLine("exception");

            //tcs.SetResult("false");

            Console.WriteLine("result");

            //return tcs.Task;  

        }

        Console.WriteLine("aaaaa");

        return tcs.Task;

    }

}