阅读1：http://blog.csdn.net/nacl025/article/details/9163495
阅读2：http://www.cnblogs.com/x-xk/archive/2013/06/05/3118005.html
阅读3：http://www.cnblogs.com/jesse2013/p/Asynchronous-Programming-In-DotNet.html#asyncwithiis
gaobing 2016-06-01 17:15 原文
阅读1：http://blog.csdn.net/nacl025/article/details/9163495
阅读2：http://www.cnblogs.com/x-xk/archive/2013/06/05/3118005.html
阅读3：http://www.cnblogs.com/jesse2013/p/Asynchronous-Programming-In-DotNet.html#asyncwithiis