Based on the implementation code of using BeginInvoke and EndInvoke asynchronously call delegates

using System;
using ;
using ;
using ;
using ;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            ("Main ThreadId = " + );
//Assign a value to the delegation
            Func<long, long> delegateMethod = new Func<long, long>(CalcSum);
//Asynchronously execute the delegation, here the delegation itself is passed in as an asyncState object. In the callback function, you need to use the delegate's EndInvoke to obtain the result.
            (200, DoneCallback, delegateMethod);
//Execute the delegation asynchronously, throw an exception
            (10000000000, DoneCallback, delegateMethod);
            ();
        }

//Delegate callback function
        static void DoneCallback(IAsyncResult asyncResult)
        {
//The delegation has been executed in the asynchronous thread here
            ("DoneCallback ThreadId = " + );

            Func<long, long> method = (Func<long, long>);
//Exception of delegated execution will be thrown when EndInvoke
            try {
//When using BeginInvoke, the entrusted EndInvoke is passed into the calculation result. At this time, the calculation result has been released. If there is an exception, it will be thrown here.
                long sum = (asyncResult);
                ("sum = {0}",sum);
            }
            catch (OverflowException)
            {
("Operation overflow");
            }
        }

//Delegation method
        static long CalcSum(long topLimit)
        {
//The delegate starts execution in another thread
            ("Calc ThreadId = " + );
            checked
            {
                long result = 0;
                for (long i = 0; i < topLimit; i++)
                {
                    result += i;
                }
                return result;
            }
        }
    }

}