两件事。

首先，你确定它是一个目录而不是过滤器吗？默认视图不代表硬盘上的物理布局。

First, are you sure that it is a directory and not a filter? The default view doesn't represent the physical layout on the hard disk.

其次，您是否显示为该项目启用的所有文件？

Second, do you have show all files enabled for that project?

注意，您必须拥有自己想要的项目将此应用于或应用其中一个子项。如果您选择了解决方案名称，则不会显示。

Note, you must have the project that you want to apply this to, or one of the sub items, to apply it. It doesn't appear if you have the solution name selected.