在MVC4中，WebAPI 404可以通过以下方式处理:

课程APICONTROLLER

    // GET /api/courses/5
    public HttpResponseMessage<Courses> Get(int id)
    {
        HttpResponseMessage<Courses> resp = null;

        var aCourse = _courses.Where(c => c.Id == id).FirstOrDefault();

        resp = aCourse == null ? new HttpResponseMessage<Courses>(System.Net.HttpStatusCode.NotFound) : new HttpResponseMessage<Courses>(aCourse);

        return resp;
    }

家控制器

public ActionResult Course(int id)
{
    return View(id);
}

VIEW

<div id="course"></div>
<script type="text/javascript">
    var id = @Model;
    var course = $('#course');
    $.ajax({    
        url: '/api/courses/' + id,
        success: function (data) {
            course.text(data.Name);
        },
        statusCode: {
            404: function() 
            {
                course.text('Course not available!');    
            }
        }
    });
</script>

全球

public static void RegisterRoutes(RouteCollection routes)
{
    routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

    routes.MapHttpRoute(
        name: "DefaultApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional }
    );

    routes.MapRoute(
        name: "Default",
        url: "{controller}/{action}/{id}",
        defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
    );
}

结果

1)创建抽象的Controller类。

public abstract class MyController:Controller
{
    public ActionResult NotFound()
    {
        Response.StatusCode = 404;
        return View("NotFound");
    }

    protected override void HandleUnknownAction(string actionName)
    {
        this.ActionInvoker.InvokeAction(this.ControllerContext, "NotFound");
    }
    protected override void OnAuthorization(AuthorizationContext filterContext) { }
}  

2)在你的所有控制器中继承这个抽象类

public class HomeController : MyController
{}  

3)在视图共享文件夹中添加一个名为“NotFound”的视图。

代码来自http://blogs.microsoft.co.il/blogs/shay/archive/2009/03/06/real-world-error-hadnling-in-asp-net-mvc-rc2.aspx，也可以在ASP.net MVC 1.0中使用

下面是我如何处理http异常:

protected void Application_Error(object sender, EventArgs e)
{
   Exception exception = Server.GetLastError();
   // Log the exception.

   ILogger logger = Container.Resolve<ILogger>();
   logger.Error(exception);

   Response.Clear();

   HttpException httpException = exception as HttpException;

   RouteData routeData = new RouteData();
   routeData.Values.Add("controller", "Error");

   if (httpException == null)
   {
       routeData.Values.Add("action", "Index");
   }
   else //It's an Http Exception, Let's handle it.
   {
       switch (httpException.GetHttpCode())
       {
          case 404:
              // Page not found.
              routeData.Values.Add("action", "HttpError404");
              break;
          case 500:
              // Server error.
              routeData.Values.Add("action", "HttpError500");
              break;

           // Here you can handle Views to other error codes.
           // I choose a General error template  
           default:
              routeData.Values.Add("action", "General");
              break;
      }
  }           

  // Pass exception details to the target error View.
  routeData.Values.Add("error", exception);

  // Clear the error on server.
  Server.ClearError();

  // Avoid IIS7 getting in the middle
  Response.TrySkipIisCustomErrors = true; 

  // Call target Controller and pass the routeData.
  IController errorController = new ErrorController();
  errorController.Execute(new RequestContext(    
       new HttpContextWrapper(Context), routeData));
}

加上我的解决方案，这几乎是相同的Herman Kan的，有一个小皱纹，让它工作在我的项目。

创建一个自定义错误控制器:

public class Error404Controller : BaseController
{
    [HttpGet]
    public ActionResult PageNotFound()
    {
        Response.StatusCode = 404;
        return View("404");
    }
}

然后创建一个自定义控制器工厂:

public class CustomControllerFactory : DefaultControllerFactory
{
    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
    {
        return controllerType == null ? new Error404Controller() : base.GetControllerInstance(requestContext, controllerType);
    }
}

最后，向自定义错误控制器添加一个覆盖:

protected override void HandleUnknownAction(string actionName)
{
    var errorRoute = new RouteData();
    errorRoute.Values.Add("controller", "Error404");
    errorRoute.Values.Add("action", "PageNotFound");
    new Error404Controller().Execute(new RequestContext(HttpContext, errorRoute));
}

就是这样。不需要网络。配置更改。

我能让@cottsak的方法为无效控制器工作的唯一方法是修改CustomControllerFactory中现有的路由请求，如下所示:

public class CustomControllerFactory : DefaultControllerFactory
{
    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
    {
        try
        {
            if (controllerType == null)
                return base.GetControllerInstance(requestContext, controllerType); 
            else
                return ObjectFactory.GetInstance(controllerType) as Controller;
        }
        catch (HttpException ex)
        {
            if (ex.GetHttpCode() == (int)HttpStatusCode.NotFound)
            {
                requestContext.RouteData.Values["controller"] = "Error";
                requestContext.RouteData.Values["action"] = "Http404";
                requestContext.RouteData.Values.Add("url", requestContext.HttpContext.Request.Url.OriginalString);

                return ObjectFactory.GetInstance<ErrorController>();
            }
            else
                throw ex;
        }
    }
}

我应该提到我使用的是MVC 2.0。

404要求

以下是我对404解决方案的要求，下面我展示了我如何实现它:

I want to handle matched routes with bad actions I want to handle matched routes with bad controllers I want to handle un-matched routes (arbitrary urls that my app can't understand) - i don't want these bubbling up to the Global.asax or IIS because then i can't redirect back into my MVC app properly I want a way to handle in the same manner as above, custom 404s - like when an ID is submitted for an object that does not exist (maybe deleted) I want all my 404s to return an MVC view (not a static page) to which i can pump more data later if necessary (good 404 designs) and they must return the HTTP 404 status code

解决方案

我认为你应该在全局中保存Application_Error。asax用于高级的事情，如未处理的异常和日志记录(如Shay Jacoby的回答所示)，但不用于404处理。这就是为什么我的建议将404内容排除在全局中。asax文件。

步骤1:为404错误逻辑设置一个公共位置

这对于可维护性来说是个好主意。使用ErrorController，以便将来对精心设计的404页面的改进可以很容易地适应。此外，确保您的响应有404代码!

public class ErrorController : MyController
{
    #region Http404

    public ActionResult Http404(string url)
    {
        Response.StatusCode = (int)HttpStatusCode.NotFound;
        var model = new NotFoundViewModel();
        // If the url is relative ('NotFound' route) then replace with Requested path
        model.RequestedUrl = Request.Url.OriginalString.Contains(url) & Request.Url.OriginalString != url ?
            Request.Url.OriginalString : url;
        // Dont get the user stuck in a 'retry loop' by
        // allowing the Referrer to be the same as the Request
        model.ReferrerUrl = Request.UrlReferrer != null &&
            Request.UrlReferrer.OriginalString != model.RequestedUrl ?
            Request.UrlReferrer.OriginalString : null;

        // TODO: insert ILogger here

        return View("NotFound", model);
    }
    public class NotFoundViewModel
    {
        public string RequestedUrl { get; set; }
        public string ReferrerUrl { get; set; }
    }

    #endregion
}

步骤2:使用一个基本的Controller类，这样就可以轻松地调用自定义404动作并连接HandleUnknownAction

404在ASP。NET MVC需要在许多地方被捕获。第一个是HandleUnknownAction。

InvokeHttp404方法为重新路由到ErrorController和新的Http404动作创建了一个公共位置。想干!

public abstract class MyController : Controller
{
    #region Http404 handling

    protected override void HandleUnknownAction(string actionName)
    {
        // If controller is ErrorController dont 'nest' exceptions
        if (this.GetType() != typeof(ErrorController))
            this.InvokeHttp404(HttpContext);
    }

    public ActionResult InvokeHttp404(HttpContextBase httpContext)
    {
        IController errorController = ObjectFactory.GetInstance<ErrorController>();
        var errorRoute = new RouteData();
        errorRoute.Values.Add("controller", "Error");
        errorRoute.Values.Add("action", "Http404");
        errorRoute.Values.Add("url", httpContext.Request.Url.OriginalString);
        errorController.Execute(new RequestContext(
             httpContext, errorRoute));

        return new EmptyResult();
    }

    #endregion
}

步骤3:在控制器工厂中使用依赖注入并连接404 httpexception

就像这样(它不一定是StructureMap):

MVC1.0例子:

public class StructureMapControllerFactory : DefaultControllerFactory
{
    protected override IController GetControllerInstance(Type controllerType)
    {
        try
        {
            if (controllerType == null)
                return base.GetControllerInstance(controllerType);
        }
        catch (HttpException ex)
        {
            if (ex.GetHttpCode() == (int)HttpStatusCode.NotFound)
            {
                IController errorController = ObjectFactory.GetInstance<ErrorController>();
                ((ErrorController)errorController).InvokeHttp404(RequestContext.HttpContext);

                return errorController;
            }
            else
                throw ex;
        }

        return ObjectFactory.GetInstance(controllerType) as Controller;
    }
}

MVC2.0例子:

    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
    {
        try
        {
            if (controllerType == null)
                return base.GetControllerInstance(requestContext, controllerType);
        }
        catch (HttpException ex)
        {
            if (ex.GetHttpCode() == 404)
            {
                IController errorController = ObjectFactory.GetInstance<ErrorController>();
                ((ErrorController)errorController).InvokeHttp404(requestContext.HttpContext);

                return errorController;
            }
            else
                throw ex;
        }

        return ObjectFactory.GetInstance(controllerType) as Controller;
    }

我认为最好是在错误产生的地方捕捉错误。这就是为什么我更喜欢上面的Application_Error处理程序。

这是第二个接404的地方。

步骤4:添加一个NotFound路由到全局。Asax用于无法解析到应用程序中的url

这个路由应该指向Http404操作。注意url参数将是一个相对url，因为路由引擎在这里剥离域部分?这就是为什么我们在步骤1中有所有的条件url逻辑。

        routes.MapRoute("NotFound", "{*url}", 
            new { controller = "Error", action = "Http404" });

这是在MVC应用程序中捕获不是自己调用的404的第三个也是最后一个地方。如果你在这里没有捕捉到不匹配的路由，那么MVC就会把这个问题传递给ASP。NET (global。asax)在这种情况下你不希望那样。

第五步:最后，当你的应用找不到东西时调用404

就像当一个坏的ID提交给我的贷款控制器(来源于MyController):

    //
    // GET: /Detail/ID

    public ActionResult Detail(int ID)
    {
        Loan loan = this._svc.GetLoans().WithID(ID);
        if (loan == null)
            return this.InvokeHttp404(HttpContext);
        else
            return View(loan);
    }

如果所有这些都能在更少的地方用更少的代码连接起来，那就太好了，但我认为这种解决方案更可维护，更可测试，而且相当实用。

谢谢你的反馈。我想要更多。

注:这已经从我原来的答案编辑显著，但目的/要求是相同的-这就是为什么我没有添加一个新的答案