在添加web service引用时查找web service，很多例子都说直接找vsdisco文件就行了，比如：http://localhost/

终于找到了一个说法：
http://msdn.microsoft.com/msdnmag/issues/02/08/XMLFiles/

In the beta releases of the .NET Framework, the .vsdisco HTTP handler was automatically enabled, but for the final release the .NET team decided to disable it by default.