参照MSDN官方说明搞定了!
设置帮助首选项不见了,不知道是取消了还是移动到其他地方去了
注释 (2)
Visual Studio Team on 2017/3/10
Thank you for your feedback. In Visual Studio 2017, the offline Help Viewer is not installed by Design. To add the offline Help Viewer: 1. In Visual Studio, select the Quick Launch search box (Ctrl+Q) 2. Type 'Help Viewer' 3. Select Help View (Individual Component) in the search result 4. Follow the prompt on the Installer, close Visual Studio and click Install.