C#如果控制器中存在过滤条件,mvc 5退出

我正试图干掉我的代码。我有一个控制器,它一次又一次地重复相同的代码位,但我无法移动到新方法,因为重复的代码包含一个return语句。

下面是一个代码示例

    public class ExampleController : Controller
{

    private Authorizer _authorizer = new Authorizer();

    public ActionResult Edit(int id)
    {
//Repeated Code Start
        var result = _authorizer.EditThing(id);
        if (result.CanEditPartA)
        {
            //log attempted bad access
            //Other repeted things 
            return View("error", result.Message);
        }
//Repeated Code End 

        //unique logic to this action. 
        return View();
    }
    public ActionResult Edit1(int id, FormCollection collection)
    {
//Repeated Code Start
        var result = _authorizer.EditThing(id);
        if (result.CanEditPartA)
        {
            //log attempted bad access
            //Other repeted things 
            return View("error", result.Message);
        }
//Repeated Code End
        //unique logic to this action.

        try
        {

            return RedirectToAction("Index");
        }
        catch
        {
            return View();
        }
    }
}

public class Authorizer
{
    // check a bunch of things and determine if person can to something

    public Result EditThing(int thingID)
    {
        //get thing from DB
        //logic of thing compared to current user
        //Create Result basied on bussness Logic
        return new Result();
    }


    public class Result
    {
        public bool CanEditPartA { get; set; }
        public bool CanEditPartB { get; set; }
        public bool CanEditPartC { get; set; }
        public string Message { get; set; }
    }
}

}

这个例子在我的实际问题“重复代码”中缩短了很多

 var result = _authorizer.EditThing(id);
        if (result.CanEditPartA)
        {
            //log attempted bad access
            //Other repeted things 
            return View("error", result.Message);
        }

我希望能做这样的事情

       public ActionResult Edit(int id)
    {

        if (CanUserEditPartA(id) != null)
        {
            return CanUserEditPartA(id);
        }

        //unique logic to this action. 
        return View();
    }

    private ActionResult CanUserEditPartA(int id)
    {
        var result = _authorizer.EditThing(id);
        if (result.CanEditPartA)
        {
            //log attempted bad access
            //Other repeted things 
            return View("error", result.Message);
        }
        return null;
    }

但问题是当我返回null时。Methoded Edit也退出。

有没有一种方法可以让助手方法在某个路径中返回ActionResult,但如果为null或其他情况,则允许在主路径上继续?