我想使用新的的HttpClient 在.NET 4.5，但Visual Studio中抱怨说，它不存在。我有 System.Net ，但是当我键入 System.Net.Http ，它抱怨了这一点。

I am trying to use the new HttpClient in .NET 4.5, but Visual Studio complains that it doesn't exist. I have System.Net, but when I type System.Net.Http, it complains for that too.

我应该下载一个新的分配该类？

Am I supposed to download a new distributable for this class?

推荐答案

添加引用 System.Net.Http ：