本文实例讲述了C#中异步回调函数用法。分享给大家供大家参考。具体如下：
static void Main(string[] args)
{
Func<string> showMessage = ShowMessage;
//设置了回调函数Completed,不能有返回值
IAsyncResult result = showMessage.BeginInvoke("测试异步委托",new AsyncCallback(Completed),null);
//半段异步是否结束
while(!result.IsCompleted)
{
Console.WriteLine
