static void Main(string[] args)
{
AsyncSum asum = Sum;
asum.BeginInvoke(100, (IAsyncResult ar) => { Console.WriteLine(asum.EndInvoke(ar)); }, null);
Console.ReadKey();
}
public static void PostAsync(int a, int b)
{
AsyncSum caller = MySum;
//FooCallBack,caller为额外的参数
caller.BeginInvoke(a, b, FooCallBack, caller); //第三个参数为回调
}