using System;

using System.Threading;

using System.Threading.Tasks;

namespace BeginEndInvokeTest

{

    public class Program

    {

        public static void Main(string[] args)

        {

            var caller = new AsyncDemo.AsyncMethodCaller(AsyncDemo.Test);

​

            var ar = caller.BeginInvoke(3000, AsyncCallback, caller);

​

            Thread.Sleep(5000);

        }

​

        static void AsyncCallback(IAsyncResult ar)

        {

            var caller = (AsyncDemo.AsyncMethodCaller) ar.AsyncState;

            try

            {

                caller.EndInvoke(ar);

                Console.WriteLine("No exception was thrown");

            }

            catch (Exception)

            {

                Console.WriteLine("Exception encountered");

            }

        }

    }

​

    public class AsyncDemo

    {

        public static string Test(int callDuration)

        {

            Console.WriteLine("Test method begins");

            Thread.Sleep(callDuration);

            throw new Exception("Testing");

        }

​

        public delegate string AsyncMethodCaller(int callDuration);

    }

}