TryUpdateModel在ASP.NET MVC 3单元测试中抛出NullReferenceException

Since I upgraded from MVC 2 to MVC 3 RC, using TryUpdateModel causes a NullReferenceException. This problem only occurs when running my action method as part of a unit test. Running it on the actual server works as expected.Since I upgraded from MVC 2 to MVC 3 RC, using