我刚在vs2008工程里加了一个.ashx,intellisense没有问题啊, google 找到了下面的文章,说的是vs2013,你可以在 你那里试一试
http://stackoverflow.com/questions/21471887/visual-studio-2013-intellisense-stops-working-for-asp-net-mvc5-controllers
大概说的是:
* 删除.suo 文件
* Tools > Import and Export Settings... > Reset all settings
* Tools > Options > Text Editor > C# > General
Make sure that "Auto List Members" is checked
* Tools -> Options
** **
Text Editor -> C# -> Intellisense
** **
Ensure "Show completion list after a character is typed" is checked