如何覆盖控制器的ActionResult方法MVC3？ [英] How to override controller actionresult method in mvc3?

问题描述

有一个名为指数HomeController的一种方法。 （它是由微软提供的只是默认模板）

There is one method called Index in HomeController. (It is just default template provided by Microsoft)

 public class HomeController : Controller
    {

        public ActionResult Index()
        {
            ViewBag.Message = "Welcome to ASP.NET MVC!";
            return View();
        }

        public ActionResult About()
        {
            return View();
        }
   }

现在我想的是，...覆盖指数的方法。类似下面。

Now What I want is that... override Index method. something like below.

public partial class HomeController : Controller
    {

        public virtual ActionResult Index()
        {
            ViewBag.Message = "Welcome to ASP.NET MVC!";
            return View();
        }

        public ActionResult About()
        {
            return View();
        }

        public override ActionResult Index()
        {
            ViewBag.Message = "Override Index";
            return View();
        }

    }

我不希望像在面向对象设计开闭原则，现有方法的任何修改。
是否有可能或不？或有另一种方式？

I don't want any modification in existing method like Open-Closed principle in OO design. Is it possible or not? or Is there another way ?

推荐答案

A 控制器是一个正常的C＃类，所以你必须遵循继承的一般规则。如果你想在同一类覆盖的方法，这是胡说八道，将无法编译。

A Controller is a normal C# class, so you have to follow the normal rules of inheritance. If you're trying to override a method in the same class, that's nonsense and will not compile.

public class FooController
{
    public virtual ActionResult Bar()
    {
    }

    // COMPILER ERROR here, there's nothing to override
    public override ActionResult Bar()
    {
    }
}

如果您有富的子类，则可以覆盖，如果在基类中的方法被标记虚拟。 （而且，如果子类没有覆盖的方法，然后在基类中的方法将被调用。）

If you have subclasses of Foo, then you can override, if the method on the base class is marked virtual. (And, if the subclass doesn't override the method, then the method on the base class will get invoked.)

public class FooController
{
    public virtual ActionResult Bar()
    {
        return View();
    }
}

public class Foo1Controller : FooController
{
    public override ActionResult Bar()
    {
        return View();
    }
}

public class Foo2Controller : FooController
{
}

因此​​，它的工作原理是这样的：

So it works like this:

Foo1 foo1 = new Foo1();
foo1.Bar();               // here the overridden Bar method in Foo1 gets called
Foo2 foo2 = new Foo2();
foo2.Bar();               // here the base Bar method in Foo gets called

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