异步调用委托的3种方法

异步调用委托的3种方法

using System;
using System.Collections.Generic;
using System.Text;

namespace AsyncDelegate
{
    class Program
    {

        delegate int IntIntDelegate(int x);//生明一个委托

        int Square(int x)
        {
            return x * x;
        }

         void AsyncDelegateExample()
        {
            
            IntIntDelegate f = Square;

            //方法一
            IAsyncResult ar1=f.BeginInvoke(10,null,null);
            while (!ar1.IsCompleted)//循环直到异步完成
                Console.WriteLine(f.EndInvoke(ar1));
            //do some work
            
             
            //方法二
            IAsyncResult ar2= f.BeginInvoke(20, null, null);
            //do some work
            ar2.AsyncWaitHandle.WaitOne();//等待直到异步完成
            Console.WriteLine(f.EndInvoke(ar2));

            //方法三  完成后调用回调函数，取得结束通知的结果
            IAsyncResult ar3 = f.BeginInvoke(30, AsyncDelegateCallback, f);

        
        }

        void AsyncDelegateCallback(IAsyncResult ar)//回调函数
        {
            IntIntDelegate f = (IntIntDelegate)ar.AsyncState;
            if (ar.IsCompleted)
            {
                Console.WriteLine(f.EndInvoke(ar));
            }

            //Console.WriteLine(f.EndInvoke(ar));
            
        }

        static void Main(string[] args)
        {
            Program test = new Program();
            test.AsyncDelegateExample();//客户端调用
        }
    }
}

输出： 100
          400
          900