删除的web.config 从查看文件夹中。

当你包括 Partial1.cshtml 从该文件夹，它也包括来自内有web.config中。这是web.config中说，所有的页面必须从WebViewPage继承。

As you're including Partial1.cshtml from that folder, it is also including the web.config from within there. And that web.config is saying that all pages must inherit from WebViewPage.