View inside an area as default in MVC

Question

How can I make a view inside an area the default when running the application?

Error I am getting:

My structure:

My file Routeconfig

What I did below didn’t work.

namespace WebApplication1
{
    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
            routes.MapRoute(
                name: "Default",
                url: "{area}/{controller}/{action}/{id}",
                defaults: new { area = "Administracao", controller = "Usuarios", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

Thank you

Answer 1

The route is ok. The big problem here is in the View Engine, that is not something simple to solve. I will translate this response from the gringo OS:

First you need to create a View Engine that looks over the areas of your project. In my projects, I use the namespace MeuProjeto.Infrastructure.ViewEngines:

Basereaawareviewengine.Cs

public abstract class BaseAreaAwareViewEngine : VirtualPathProviderViewEngine
{
    private static readonly string[] EmptyLocations = { };

    public override ViewEngineResult FindView(
        ControllerContext controllerContext, string viewName,
        string masterName, bool useCache)
    {
        if (controllerContext == null)
        {
            throw new ArgumentNullException("controllerContext");
        }
        if (string.IsNullOrEmpty(viewName))
        {
            throw new ArgumentNullException(viewName,
                "Value cannot be null or empty.");
        }

        string area = getArea(controllerContext);
        return FindAreaView(controllerContext, area, viewName,
            masterName, useCache);
    }

    public override ViewEngineResult FindPartialView(
        ControllerContext controllerContext, string partialViewName,
        bool useCache)
    {
        if (controllerContext == null)
        {
            throw new ArgumentNullException("controllerContext");
        }
        if (string.IsNullOrEmpty(partialViewName))
        {
            throw new ArgumentNullException(partialViewName,
                "Value cannot be null or empty.");
        }

        string area = getArea(controllerContext);
        return FindAreaPartialView(controllerContext, area,
            partialViewName, useCache);
    }

    protected virtual ViewEngineResult FindAreaView(
        ControllerContext controllerContext, string areaName, string viewName,
        string masterName, bool useCache)
    {
        string controllerName =
            controllerContext.RouteData.GetRequiredString("controller");
        string[] searchedViewPaths;
        string viewPath = GetPath(controllerContext, ViewLocationFormats,
            "ViewLocationFormats", viewName, controllerName, areaName, "View",
            useCache, out searchedViewPaths);
        string[] searchedMasterPaths;
        string masterPath = GetPath(controllerContext, MasterLocationFormats,
            "MasterLocationFormats", masterName, controllerName, areaName,
            "Master", useCache, out searchedMasterPaths);
        if (!string.IsNullOrEmpty(viewPath) &&
            (!string.IsNullOrEmpty(masterPath) || 
              string.IsNullOrEmpty(masterName)))
        {
            return new ViewEngineResult(CreateView(controllerContext, viewPath,
                masterPath), this);
        }
        return new ViewEngineResult(
            searchedViewPaths.Union<string>(searchedMasterPaths));
    }

    protected virtual ViewEngineResult FindAreaPartialView(
        ControllerContext controllerContext, string areaName,
        string viewName, bool useCache)
    {
        string controllerName =
            controllerContext.RouteData.GetRequiredString("controller");
        string[] searchedViewPaths;
        string partialViewPath = GetPath(controllerContext,
            ViewLocationFormats, "PartialViewLocationFormats", viewName,
            controllerName, areaName, "Partial", useCache,
            out searchedViewPaths);
        if (!string.IsNullOrEmpty(partialViewPath))
        {
            return new ViewEngineResult(CreatePartialView(controllerContext,
                partialViewPath), this);
        }
        return new ViewEngineResult(searchedViewPaths);
    }

    protected string CreateCacheKey(string prefix, string name,
        string controller, string area)
    {
        return string.Format(CultureInfo.InvariantCulture,
            ":ViewCacheEntry:{0}:{1}:{2}:{3}:{4}:",
            base.GetType().AssemblyQualifiedName,
            prefix, name, controller, area);
    }

    protected string GetPath(ControllerContext controllerContext,
        string[] locations, string locationsPropertyName, string name,
        string controllerName, string areaName, string cacheKeyPrefix,
        bool useCache, out string[] searchedLocations)
    {
        searchedLocations = EmptyLocations;
        if (string.IsNullOrEmpty(name))
        {
            return string.Empty;
        }
        if ((locations == null) || (locations.Length == 0))
        {
            throw new InvalidOperationException(string.Format("The property " +
                "'{0}' cannot be null or empty.", locationsPropertyName));
        }
        bool isSpecificPath = IsSpecificPath(name);
        string key = CreateCacheKey(cacheKeyPrefix, name,
            isSpecificPath ? string.Empty : controllerName,
            isSpecificPath ? string.Empty : areaName);
        if (useCache)
        {
            string viewLocation = ViewLocationCache.GetViewLocation(
                controllerContext.HttpContext, key);
            if (viewLocation != null)
            {
                return viewLocation;
            }
        }
        if (!isSpecificPath)
        {
            return GetPathFromGeneralName(controllerContext, locations, name,
                controllerName, areaName, key, ref searchedLocations);
        }
        return GetPathFromSpecificName(controllerContext, name, key,
            ref searchedLocations);
    }

    protected string GetPathFromGeneralName(ControllerContext controllerContext,
        string[] locations, string name, string controllerName,
        string areaName, string cacheKey, ref string[] searchedLocations)
    {
        string virtualPath = string.Empty;
        searchedLocations = new string[locations.Length];
        for (int i = 0; i < locations.Length; i++)
        {
            if (string.IsNullOrEmpty(areaName) && locations[i].Contains("{2}"))
            {
                continue;
            }
            string testPath = string.Format(CultureInfo.InvariantCulture,
                locations[i], name, controllerName, areaName);
            if (FileExists(controllerContext, testPath))
            {
                searchedLocations = EmptyLocations;
                virtualPath = testPath;
                ViewLocationCache.InsertViewLocation(
                    controllerContext.HttpContext, cacheKey, virtualPath);
                return virtualPath;
            }
            searchedLocations[i] = testPath;
        }
        return virtualPath;
    }

    protected string GetPathFromSpecificName(
        ControllerContext controllerContext, string name, string cacheKey,
        ref string[] searchedLocations)
    {
        string virtualPath = name;
        if (!FileExists(controllerContext, name))
        {
            virtualPath = string.Empty;
            searchedLocations = new string[] { name };
        }
        ViewLocationCache.InsertViewLocation(controllerContext.HttpContext,
            cacheKey, virtualPath);
        return virtualPath;
    }


    protected string getArea(ControllerContext controllerContext)
    {
        // First try to get area from a RouteValue override, like one specified in the Defaults arg to a Route.
        object areaO;
        controllerContext.RouteData.Values.TryGetValue("area", out areaO);

        // If not specified, try to get it from the Controller's namespace
        if (areaO != null)
            return (string)areaO;

        string namespa = controllerContext.Controller.GetType().Namespace;
        int areaStart = namespa.IndexOf("Areas.");
        if (areaStart == -1)
            return null;

        areaStart += 6;
        int areaEnd = namespa.IndexOf('.', areaStart + 1);
        string area = namespa.Substring(areaStart, areaEnd - areaStart);
        return area;
    }

    protected static bool IsSpecificPath(string name)
    {
        char ch = name[0];
        if (ch != '~')
        {
            return (ch == '/');
        }
        return true;
    }
}

As the class is abstract, you will also need to create the class that derives BaseAreaAwareViewEngine:

Areaawareviewengine.Cs

public class AreaAwareViewEngine : BaseAreaAwareViewEngine
{
    public AreaAwareViewEngine()
    {
        MasterLocationFormats = new string[]
        {
            "~/Areas/{2}/Views/{1}/{0}.master",
            "~/Areas/{2}/Views/{1}/{0}.cshtml",
            "~/Areas/{2}/Views/Shared/{0}.master",
            "~/Areas/{2}/Views/Shared/{0}.cshtml",
            "~/Views/{1}/{0}.master",
            "~/Views/{1}/{0}.cshtml",
            "~/Views/Shared/{0}.master"
            "~/Views/Shared/{0}.cshtml"
        };
        ViewLocationFormats = new string[]
        {
            "~/Areas/{2}/Views/{1}/{0}.aspx",
            "~/Areas/{2}/Views/{1}/{0}.ascx",
            "~/Areas/{2}/Views/{1}/{0}.cshtml",
            "~/Areas/{2}/Views/Shared/{0}.aspx",
            "~/Areas/{2}/Views/Shared/{0}.ascx",
            "~/Areas/{2}/Views/Shared/{0}.cshtml",
            "~/Views/{1}/{0}.aspx",
            "~/Views/{1}/{0}.ascx",
            "~/Views/{1}/{0}.cshtml",
            "~/Views/Shared/{0}.aspx"
            "~/Views/Shared/{0}.ascx"
            "~/Views/Shared/{0}.cshtml"
        };
        PartialViewLocationFormats = ViewLocationFormats;
    }

    protected override IView CreatePartialView(
        ControllerContext controllerContext, string partialPath)
    {
        if (partialPath.EndsWith(".cshtml"))
            return new System.Web.Mvc.RazorView(controllerContext, partialPath, null, false, null);
        else
            return new WebFormView(controllerContext, partialPath);
    }

    protected override IView CreateView(ControllerContext controllerContext,
        string viewPath, string masterPath)
    {
        if (viewPath.EndsWith(".cshtml"))
            return new RazorView(controllerContext, viewPath, masterPath, false, null);
        else
            return new WebFormView(controllerContext, viewPath, masterPath);
    }
}

Note that MasterLocationFormats changes the search priority of View Engine to first look at the areas.

        MasterLocationFormats = new string[]
        {
            "~/Areas/{2}/Views/{1}/{0}.master",
            "~/Areas/{2}/Views/{1}/{0}.cshtml",
            "~/Areas/{2}/Views/Shared/{0}.master",
            "~/Areas/{2}/Views/Shared/{0}.cshtml",
            "~/Views/{1}/{0}.master",
            "~/Views/{1}/{0}.cshtml",
            "~/Views/Shared/{0}.master"
            "~/Views/Shared/{0}.cshtml"
        };

Now you will need to register the View Engine in the Global.asax.cs:

Global.asax.Cs

protected void Application_Start()
{
    RegisterRoutes(RouteTable.Routes);
    ViewEngines.Engines.Clear();
    ViewEngines.Engines.Add(new AreaAwareViewEngine());
}

That alone is enough to work. The answer details a few more things, but roughly speaking, this is it.