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;             }         }     } }