这一个是用户错误。

我只是偶然发现了这个计算器的其他问题：web-service净4-0 返回XML而不是JSON的

I just stumbled upon this other *** question: web-service returning xml instead of json in net 4-0

一个类似的解决方案竟然是我需要的。 web.config文件中曾经为ScriptHandlerFactory的IIS6一个HttpHandler映射，我是用IIS7。添加的HttpHandler映射到web.config的IIS7部分解决了这个问题。

A similar solution turned out to be what I needed. The web.config file had an httpHandler mapping for the ScriptHandlerFactory for IIS6, and I was using IIS7. Adding the httpHandler mapping to the IIS7 section of the web.config solved the problem.

我不喜欢隐藏的移动部件....

I hate hidden moving parts....