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ASP.NET MVC - How do I Call a Controller Method from within a View to Redirect to Multiple Other Views?

I am trying to add a single link in my navbar that redirects the user to a different webpage depending on their account type. I am having issues doing this and could use some help.
The Controller code that I am calling looks like this:
public IActionResult Attendance(char accountType)
{
if (accountType.Equals("m") || accountType.Equals("a"))
{
return RedirectToAction("FacultyAttendance");
}
else
{
return RedirectToAction("StudentAttendance");
}
}
public IActionResult StudentAttendance()
{
// More functionality will be added later
return View();
}
public IActionResult FacultyAttendance()
{
// More functionality will be added later
return View();
}
Following this answer for calling the Controller method, I have this code snippet in the View file:
Attendance
This gives me the following error:
Bad Request - Invalid URL
HTTP Error 400. The request URL is invalid.
I also tried following this answer by removing the <%: and %>.
Attendance
If I do this, I just get blank webpage.
My first problem lies in which style I should use for this method call within the View file. Are either of these correct, or should I use something else entirely? Might the issue be with the way I have the Controller code set up?
Any help would be appreciated, as I am new to the MVC framework for ASP.NET.
Edit: The solution I found is a bit different than what I originally posted. I used this tag in my View and got it to work:
<a asp-controller="Home" asp-action="Attendance" asp-route-accountType='s'>Attendance</a>
I also followed ThisGuy's suggestions for improving the code since I had mismanaged some variables and that may have been part of the problem.

accountType is a char, but you are passing a string:
new {accountType = "m"}
Change the Controller to take a string instead of char for accountType.
public IActionResult Attendance(string accountType)
Also, I'd write it like this:
public IActionResult Attendance(string accountType) =>
RedirectToAction(
accountType.Equals("m") ||
accountType.Equals("a")
? nameof(FacultyAttendance)
: nameof(StudentAttendance));

ASP net MVC5 "view validation if only routed from another controller not by typing in address bar"

I have controller where inside are 2 methods , the validation is a code, if it is correct then call the another method in different controller, but there is a problem if someone write in the address bar the controller for example home/sdata/display then it retrieve the data without writing the password(code) how can i prevent to display the data until he writes the code
public ActionResult predata()
{
return View();
}
[Authorize]
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult prerest(string paswd)
{
if (paswd == "123456852")
{
return RedirectToAction("sdata","displays");
}
return View();
}

Do the validation check in the sdata Controller's displays method. If the password not right, redirect to some other page or just display an empty view.

If you add [Authorize] this problem will not exist. Probably you made something wrong with authorization. You should check more about authorization patterns for example Token Based Authentication - OWIND etc.

Controller hangs when opened using url in mvc 5

I'm new on asp.net mvc. I created a basic controller and I tried to open it using url. But rendering is not finished and my controller didn't display in several minutes. I did not change anything from default asp.net 5 mvc project also my controller's index method return only hello world string. I don't is there any problem on iis or VS. Any idea about that problem?
Thanks for help.

In MVC only public methods that return an ActionResult are accessible as web pages.
So you MUST use something like this:
public class HelloWorldController : Controller
{
// GET: HelloWorld/Index
public ActionResult Index()
{
return Content("This is <b>Index</b> action...");
}
// etc
}
Content(...) is a special method the wraps text into an ActionResult.
Note: only use Content(...) if you specifically do NOT want to use a View such as Index.cshtml - which is what you normally WOULD do, of course.

Is it safe to use query string in a post action?

I've got two controller actions at the moment: one that displays a strongly typed view, based on an unique identifier and another one that changes the model. Here's some code to visualize what I mean:
[HttpGet]
[ActionName("Edit")]
public ActionResult UpdateDevice(string code)
{
// Request the device based on the code.
var device = GetDeviceModel(code);
// Present the device in a view.
return View(device);
}
[HttpPost]
[ActionName("Edit")]
public ActionResult UpdateDevice(DeviceModel model)
{
}
The code identifies the device, but it is also possible to change it. And that's my problem: Inside the post method I can access the new code using model.Code, but I also need to know the old code, to be able to change it.
I tried several alternatives, but none of them did satisfy my requirements:
ViewData does not get persisted until the post.
TempData is based on Sessions or Cookies – none of them I want to use at the moment.
Hidden fields and model bindings are not an option, because they can be manipulated on client side.
Finally I tried requesting data from the query string like this:
[HttpPost]
[ActionName("Edit")]
public ActionResult UpdateDevice(DeviceModel model)
{
var oldCode = Request.QueryString["code"];
}
And this works! But I haven't found any resources on this around the web. So my question is: Is using the query string inside a post action safe against modifications? And what (if there are any) are the conditions for this to work?
If this is not a valid way to "remember" the code, are there any alternatives?

Based on the requirements you have mentioned in your question, it seems that you are looking for safety in the case. So I would say that QueryString is not safe. In my opinion using Session variables is the appropriate method that keeps your critical data in a safe location. You can use the method like this
[HttpGet]
[ActionName("Edit")]
public ActionResult UpdateDevice(string code)
{
Session["code"] = code;
....
}
[HttpPost]
[ActionName("Edit")]
public ActionResult UpdateDevice(DeviceModel model)
{
if (Session["code"] == null)
throw new Exception("Error Message.");
var code = Session["code"].ToString();
....
Session["code"] = null;
}

I think you can make another property inside DeviceModel name OldCode.
and in your view you can save this value in hiddenfield like this
#Html.HiddenFor(m=>m.OldCode)
Now in controller post method you can get both the values like this.
[HttpPost]
[ActionName("Edit")]
public ActionResult UpdateDevice(DeviceModel model)
{
var oldcode=model.OldCode;
var newcode=model.Code;
}
Hope this helps...

Nothing submitted via a GET or a POST request is safe from modifications. While a GET query string is obviously easy to modify, it doesn't take much effort to spoof POST variables either. It sounds to me like you need to re-think your approach.
Optimally, you would do permission checking server-side to determine if the user is allowed to update the device with the passed (old) code. If they do not have permission, return an error such as an HTTP 550 code.
If you truly can't support this approach, I would suggest adding an "OldCode" field to the DeviceModel class as suggested by others, but encrypting it before sending it to the client. Then you can safely write it to a hidden field, and decrypt back on the server without fear of the user changing the value.

ASP.NET MVC 4 Make a page not directly reachable

I have a ASP.NET MVC 4 Blog which is 90% done but i need one thing - i have a webpage lets say index/secretPage but i want to be able to navigate to this webPage only after i am redirected from another - lets say index/redirect . If the adress is hardcoded it should not navigate, if the visitor is coming from a different link like blog/post/24 it should not be able to navigate too.
I hope my question was clear, than you for all help.

You could also mask the secret page with an action that shows another page if direct called.
In this example there are 2 actions. 'Secret' for returning a bogus view and the 'Check' for the real call. In this action the bool variable 'allowSecret' ist checked an then the user sees the view 'secret.cshtml' if allowed or 'index.cshtml' if not.
Here's an example code for a simple controller with that functionality:
using System.Web.Mvc;
namespace Test.Controllers
{
public class HomeController : Controller
{
public ActionResult Index()
{
return View("Index");
}
public ActionResult Check()
{
// check if user is allowed to show secret page
if(allowSecret == true)
return View("Secret");
// Otherwise return view 'index.cshtml'
return View();
}
public ActionResult Secret()
{
// Always shows view 'index.cshtml' if url is ".../secret"
return View("Index");
}
}
}
You could also redirect to another action after the check fails instead of calling a 'fake-view':
return RedirectToAction("Index")
The difference is the url the user sees in the browser. Returning a view does not change the url, redirecting to another action changes the url to the changed route.
Of course you can place the check in another class behind the controller.
Another option is to use the 'NonAction' attribute:
[NonAction]
public ActionResult Check()
{
...
}
Hope that helps with kind regards,
DD

You can UrlReferrer to get to know who refred to this current page and throw and exception or redirect back
HttpContext.Current.Request.UrlReferrer
http://msdn.microsoft.com/en-IN/library/system.web.httprequest.urlreferrer.aspx
But for what ever reason you need this. It dosenot look like a good design to me.
Hope this helps