如何在ASP.Net MVC 3中重定向到ActionResult中的路由

Question

I am trying to create an access denied ActinoResult to return from my controllers. I have the following implementation

public class AccessDeniedResult : ActionResult
{
    public override void ExecuteResult(ControllerContext context)
    {
        if (null != context && null != context.HttpContext && null != context.HttpContext.Response)
        {
            context.HttpContext.Response.StatusCode = 401;
            context.HttpContext.Response.RedirectToRoute("AccessDenied");
        }
    }
}

This does not work because of a NotImplementedException coming from HttpResponseBase being passed as context.HttpContext.Response.

How do you write a correct redirecting action result in MVC3?

Answer 1

You should be returning HttpUnauthorizedResult like so:

return new HttpUnauthorizedResult();

Additionally, you should consider creating a new class deriving from AuthorizeAttribute to do security checks. You can then add this directive to your web.config to control where the client is directed:

<customErrors mode="On" defaultRedirect="~/Home/Error">
    <error statusCode="401" redirect="~/AccessDenied" />
</customErrors>

Finally, you can add a custom route to control what happens when the user is directed to ~/AccessDenied:

Route route = routes.MapRoute("AccessDeniedRoute", "AccessDenied", new { controller = "MyCustomErrorController", action = "My401Action" });
RouteTable.Routes.Add(route);

Answer 2

Maybe you should try inheriting from RedirectToRouteResult(which inherits ActionResult).

You can also look at the source code for that class to see how they do it:

public override void ExecuteResult(ControllerContext context) {
    if (context == null) {
        throw new ArgumentNullException("context");
    }
    if (context.IsChildAction) {
        throw new InvalidOperationException(MvcResources.RedirectAction_CannotRedirectInChildAction);
    }

    string destinationUrl = UrlHelper.GenerateUrl(RouteName, null /* actionName */, null /* controllerName */, RouteValues, Routes, context.RequestContext, false /* includeImplicitMvcValues */);
    if (String.IsNullOrEmpty(destinationUrl)) {
        throw new InvalidOperationException(MvcResources.Common_NoRouteMatched);
    }

    context.Controller.TempData.Keep();

    if (Permanent) {
        context.HttpContext.Response.RedirectPermanent(destinationUrl, endResponse: false);
    }
    else {
        context.HttpContext.Response.Redirect(destinationUrl, endResponse: false);
    }
}