使用BeginInvoke,EndInvoke异步调用委托

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Threading; 
  
namespace ConsoleApplication1 
{ 
    class Program 
    { 
        static void Main(string[] args) 
        { 
            Console.WriteLine("Main ThreadId = " + Thread.CurrentThread.ManagedThreadId); 
            //给委托赋值 
            Func<long, long> delegateMethod = new Func<long, long>(CalcSum); 
            //异步执行委托,这里把委托本身作为asyncState对象传进去，在回调函数中需要使用委托的EndInvoke来获得结果 
            delegateMethod.BeginInvoke(200, DoneCallback, delegateMethod); 
            //异步执行委托,抛出异常 
            delegateMethod.BeginInvoke(10000000000, DoneCallback, delegateMethod); 
            Console.ReadLine(); 
        } 
  
        //委托回调函数 
        static void DoneCallback(IAsyncResult asyncResult) 
        { 
            //到这儿委托已经在异步线程中执行完毕 
            Console.WriteLine("DoneCallback ThreadId = " + Thread.CurrentThread.ManagedThreadId); 
  
            Func<long, long> method = (Func<long, long>)asyncResult.AsyncState; 
            //委托执行的异常会在EndInvoke时抛出来 
            try { 
                //使用BeginInvoke时传入委托的EndInvoke获得计算结果，这时候计算结果已经出来了，有异常的话也在这儿抛出来 
                long sum = method.EndInvoke(asyncResult); 
                Console.WriteLine("sum = {0}",sum); 
            } 
            catch (OverflowException) 
            { 
                Console.WriteLine("运算溢出了"); 
            } 
        } 
  
        //委托方法 
        static long CalcSum(long topLimit) 
        { 
            //委托在另一个线程中开始执行 
            Console.WriteLine("Calc ThreadId = " + Thread.CurrentThread.ManagedThreadId); 
            checked
            { 
                long result = 0; 
                for (long i = 0; i < topLimit; i++) 
                { 
                    result += i; 
                } 
                return result; 
            } 
        } 
    } 
  
}