CODEWITHSUNDEEP
asp.netasp.net-mvc
Dvojrak
Dvojrak

Reputation:

ASP.NET - ActionResult parameter is coming back null always when passing string - why?

I am barely starting out with my first project on the ASP.NET MVC project type and I am creating a Details page where instead of passing the templated (int id), I would like to pass a string instead. But when I am in debug mode, and enter this in the URL, "myString" is null. Why so? Do I have to change anything else somehwere else?

So if I go to the URL and enter this:

http://localhost:2345/Bank/EmployeeDetails/3d34xyz

public ActionResult EmployeeDetails(string myString) // myString is null
{
     return View();
}

Upvotes: 10

Views: 20395

Answers (6)

István Zsigovics
István Zsigovics

Reputation: 29

And when you have tryed all of them and still it comes back null then give a full restart for Visual Studio. That's what eventually helped for me.

Upvotes: 0

Kushal
Kushal

Reputation: 17

I had the same problem, you just need to provide the id in the page where you the hyperlink for Details(in the Bank page here)

 @Html.ActionLink("Details", "Details", new { id=""})

This solved my problem hope it helps you.

This for MVC 5.

Upvotes: 0

Tomas Aschan
Tomas Aschan

Reputation: 60624

In you Global.asax.cs file, you will have the following route mapped by default:

routes.mapRoute(
    "Default",
    "{controller}/{action}/{id}",
    new { controller = "Home", action = "Index", id = UrlParameter.Optional });

That means that an url like http://localhost:2345/Bank/EmployeeDetails/3d34xyz will go to the Bank controller, the EmployeeDetails action and pass the value 3d34xyz into a parameter named id. It is perfectly alright to pass a string, but in order to make it work you have two options:

1) Rename the variable to id in your action method.

public ActionResult EmployeeDetails(string id) { ... }

2) Add another route that matches whatever name you want for your string. Make sure to make it more specific than the default route, and to place it before the default route in the Global.asax.cs file.

routes.mapRoute(
    "BankEmployeeDetails"
    "Bank/EmployeeDetails/{myString}"
    new { controller = "Bank", action = "EmployeeDetails", myString = UrlParameter.Optional });

This will pass a default value of null to myString if no value is passed in the url, but with the url you specified you will pass the value 3d34xyz.

Upvotes: 39

David P
David P

Reputation: 3634

Assuming you haven't modified the default routes (In your Global.asax.cs):

        routes.MapRoute(
            "Default",                                              // Route name
            "{controller}/{action}/{id}",                           // URL with parameters
            new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
        );

The method is expecting it to be named "id".

Upvotes: 5

Daniel Earwicker
Daniel Earwicker

Reputation: 116674

Change the name of myString to id.

Upvotes: 4

Mehrdad Afshari
Mehrdad Afshari

Reputation: 422046

Rename myString to id if you are using the default route table.

Upvotes: 5

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