Question

Goal:

I want to achieve two parameters (one string and one bool) to my actionresult Anvandare_Listaa.

    //
    // GET: /Admin/Anvandare_Listaa

    public ActionResult Anvandare_Listaa(string pAnvandaren, bool pBlivenAdministrator)
    {
        return View("Anvandare_Lista");
    }

Problem:
Can’t recieve bool value pBlivenAdministrator in my action result. I recieve error message.

The parameters dictionary contains a
null entry for parameter
‘pBlivenAdministrator’ of non-nullable
type ‘System.Boolean’ for method
‘System.Web.Mvc.ActionResult
Anvandare_Listaa(Boolean)’ in
‘BokButik1.Controllers.AdminController’.
An optional parameter must be a
reference type, a nullable type, or be
declared as an optional parameter.
Parameter name: parameters

If I use bool? instead of bool I won’t get any value. There is no problem when I use string, it is only problem related to bool in the action result.

public class MvcApplication : System.Web.HttpApplication
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

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

    }

    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();

        RegisterRoutes(RouteTable.Routes);
    }
}

---

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Admin.Master" Inherits="System.Web.Mvc.ViewPage<BokButik1.ViewModels.AllaAnvandareViewModel>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Användare Lista
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <h2>Användare Lista</h2>

    <table>
    <tr>
        <th>Användare</th>
        <th>E-post</th>
        <th>Administratör</th>
    </tr>

<% foreach (var user in Model.AllaAnvandare) { %>

    <tr>
        <td>
            <%: user.Anvandaren %>
        </td>

        <td>
            <%: user.Epost%>
        </td>
        <td>
            <%: user.BlivenAdministrator %>
        </td>
        <td>

            <%: Html.ActionLink(Html.OmAdministratorBehorighet(user.BlivenAdministrator), 
                "Anvandare_Listaa", "Admin", new {pAnvandaren = user.Anvandaren, pBlivenAdministrator = user.BlivenAdministrator }) %>
        </td>
    </tr>

<% } %>
</table>

---

Answer 1

When you generate your action link:

<%: Html.ActionLink(
    Html.OmAdministratorBehorighet(user.BlivenAdministrator), 
    "Anvandare_Listaa", 
    "Admin", 
    new {
        pAnvandaren = user.Anvandaren, 
        pBlivenAdministrator = user.BlivenAdministrator 
    }
) %>

you should make sure that the pBlivenAdministrator parameter is assigned a value so that the generated HTML looks like this:

<a href="/Admin/Anvandare_Listaa?pAnvandaren=abc&amp;pBlivenAdministrator=true">
    Some Text
</a>

If the request doesn’t contain the pBlivenAdministrator parameter you will be getting this exception. So it should be either:

/Admin/Anvandare_Listaa?pBlivenAdministrator=true

or:

/Admin/Anvandare_Listaa?pBlivenAdministrator=false