强制转换返回类型

我想使用PostSharp跟随代码:

class Program
{
    [PostModerator]
    public static ReturnState<Person> GetPerson()
    {
        return new ReturnState<Person>() { Result = new Person { Id = 2, Name = "Gholzam" }, Succeed = true };
    }
    static void Main(string[] args)
    {
        var personAttempt= GetPerson();
        Console.WriteLine("Test ok");
        Console.ReadKey();
    }
}

在PostModerator中我使用以下代码:

[Serializable]
public class PostModeratorAttribute : OnMethodBoundaryAspect
{
    public override void OnEntry(MethodExecutionArgs args)
    {
        args.ReturnValue = new ReturnState<object> { Succeed=false };//Star
        args.FlowBehavior = FlowBehavior.Return;
        for (int counter = 0; counter < args.Arguments.Count; counter++)
        {
            Console.WriteLine("arg{0} is {1}",counter,args.Arguments[counter]);
        }
        Console.WriteLine("On Entry");
    }
}

当我返回new ReturnState<object>..和Postshop尝试转换为ReturnState<Person>时，我已经cast异常，但不能。