如何正确地从控制器返回视图？

Question

I have an application with login. I have a controller and a view. From controller, I try to decide if the user is admin or not, and then to show a specific message in view.

The problem is that when I run the application from Startup and I press the login button, the application redirects me to the home page. When I run the application from the view, it works (it's stupid, but it works).

The link when I run the app prof Startup: localhost:2627/Account/Login
The link when I run the app from view: localhost:2627/Account/LoginReturnUrl=%2FUsers%2FIndex

This is my controller:

public class UsersController : Controller
{
    // GET: Users
    [Authorize]
    public ActionResult Index()
    {
        if (User.Identity.IsAuthenticated)
        {
            var user = User.Identity;
            ViewBag.Name = user.Name;

            ViewBag.displayMenu = "No";

            if (isAdminUser())
            {
                ViewBag.displayMenu = "Yes";
            }
            return View();
        }
        else
        {
            ViewBag.Name = "Not Logged IN";
        }
        //return View();
        return View();

    }

This is my View:

  @{
        ViewBag.Title = "Index";
    }
    @if (ViewBag.displayMenu == "Yes")
    {
        <h1>Welcome Admin. Now you can create user Role.</h1>
        <h3>
            <li>@Html.ActionLink("Manage Role", "Index", "Role")</li>
        </h3>
    }
    else
    {
        <h2>  Welcome <strong>@ViewBag.Name</strong> :) .We will add user module soon </h2>
    }  

I was trying to follow this tutorial(the login part). I can't figure out why it doesn't open my view. The user is authenticated, but I only see home view.

What am I doing wrong? Do you have any suggestions?

Thank you!

Answer 1

The reason it's working when you start the app from the User's view is that you are trying to access a protected resource ( ie, a resource that requires authentication). When the user is not authenticated, the default behavior is to challenge the user ( ie, authenticate the user) and the user is redirected to a login page. When the user is redirected, the returnUrl query parameter is being set so that the user can be redirected back to this resource after authentication. In this case, the returnUrl is the User's index view.

The link when I run the app from view:localhost:2627/Account/LoginReturnUrl=%2FUsers%2FIndex

It sounds like you want the Users view to be your homepage or at least the page that the user is redirected to after login. In your AccountController , you will want to force this action if this is the desired behavior.

for example:

   switch (result)   
        {   
            case SignInStatus.Success:   
                return return RedirectToAction("Index", "Users");
             ...
       }

You will also want to beware if a returnUrl is present too. Based on your requirements, you might want to give the returnUrl the highest precedence.

            If ( SignInStatus.Success)
            {
                return !string.IsNullOrEmpty(returnUrl) ?
                       RedirectToLocal(returnUrl):
                       RedirectToAction("Index", "Users");
            }

Basically, it really comes down to where you want to send (aka route) the user after authentication. Maybe the user has a preference for their home page or that if the user is an admin that you always route them to the index view in the UsersController .

In the demo project, you should review the Start.Auth.cs file and become familiar with the authentication options.

For example, the LoginPath is being set in this file. This is the path that user will be redirected to for authentication challenges.

        // Enable the application to use a cookie to store information for the signed in user
        // and to use a cookie to temporarily store information about a user logging in with a third party login provider
        // Configure the sign in cookie
        app.UseCookieAuthentication(new CookieAuthenticationOptions
        {
            AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
            LoginPath = new PathString("/Account/Login"),
            Provider = new CookieAuthenticationProvider
            {...}

        });  

Reference RedirectToAction:

http://msdn.microsoft.com/en-us/library/dd470594.aspx