使用C＃，Visual Studio 2010中。

Using C#, Visual Studio 2010.

有一个名为 System.Web.Mvc 记录在MSDN上的命名空间。该文档该命名空间的所有类型的说，他们是在 System.Web.Mvc.dll程序。

There is a namespace called System.Web.Mvc documented on MSDN. The documentation for all the types in that namespace says that they are in System.Web.Mvc.dll.

然而，当我去添加引用，。NET选项卡上，这个组件列表中缺少。为什么呢？

However, when I go to Add Reference, ".NET" tab, this assembly is missing from the list. Why?

推荐答案

所需的组件已经出现在现在列表中。

The desired assembly has appeared in the list now.

我只能猜测是什么原因导致它出现，但我怀疑它是我去的事实的文件的→新→项目的→ ASP.NET Web应用程序的，这是我从来没有做过的。它是可能的，这引起了列表某种晚初始化的情况发生，也可以填充额外组件的Web开发

I can only speculate what caused it to appear, but I suspect it is the fact that I went File → New → Project → ASP.NET Web Application, which I had never done before. It is possible that this caused some sort of late initialisation to happen and the list to be populated with additional assemblies for Web development.