Provided for backward compatibility with ASP.NET MVC 3.
来源是：
public abstract class AsyncController : Controller
{
}
我不能找到任何关于这个类在MSDN的废弃的文档。我应该替换使用AsyncController到控制器？
解决方法
Should I use AsyncController at ASP.NET MVC 4?
没有。
Should I replace uses of AsyncController to Controller?
是的，异步操作以新的方式在asp.net-mvc 4中使用Task Class实现
The ASP.NET MVC 4 Controller class in combination .NET 4.5 enables
you to write asynchronous action methods that return an object of type
Task. The .NET Framework 4 introduced an asynchronous
programming concept referred to as a Task and ASP.NET MVC 4 supports
Task. Tasks are represented by the Task type and related types in the
System.Threading.Tasks namespace. The .NET Framework 4.5 builds on
this asynchronous support with the await and async keywords that make
working with Task objects much less complex than prevIoUs asynchronous
approaches. The await keyword is syntactical shorthand for indicating
that a piece of code should asynchronously wait on some other piece of
code. The async keyword represents a hint that you can use to mark
methods as task-based asynchronous methods. The combination of await,
async,and the Task object makes it much easier for you to write
asynchronous code in .NET 4.5. The new model for asynchronous methods
is called the Task-based Asynchronous Pattern (TAP). This tutorial
assumes you have some familiarity with asynchronous programing using
await and async keywords and the Task namespace.
