根据属性WebMethod的文档：

According to the documentation of the attribute WebMethod:

https://msdn.microsoft.com/en- us / library / byxd99hx（v = vs.90）.aspx

附加 WebMethod 属性为公共方法表示您希望该方法作为XML Web服务的一部分公开。您还可以使用此属性的属性来进一步配置XML Web服务方法的行为。有关更多信息，请参阅托管代码中的XML Web服务的代码模型。

Attaching the WebMethod attribute to a Public method indicates that you want the method exposed as part of the XML Web service. You can also use the properties of this attribute to further configure the behavior of the XML Web service method. For more information, see Code Model for XML Web Services in Managed Code.

我想，Jon Skeet是对的。 ：）

I guess, Jon Skeet is right. :)