基于使用BeginInvoke,EndInvoke异步调用委托的实现代码

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;
            }
        }
    }

}