static void Main(string[] args)
{
var d = new MyAction(xxx);
var asyncResult = d.BeginInvoke(2000, ad, d);
Console.WriteLine("委托内的方法正在执行中");
//while (!asyncResult.AsyncWaitHandle.WaitOne(100, false))
//{
// Console.Write("*");
//}
//var result = d.EndInvoke(asyncResult);
//d.BeginInvoke(h => { Console.WriteLine("返回值是{0}", d.EndInvoke(h).result); }, null);
//Console.WriteLine("返回值是{0}", result.result);
Console.ReadKey();
}