Question

I am trying to understand why I get an exception when I try to get elements from a string array containing roles for my application.

error: Object reference not set to an instance of an object.
(ViewBag.roles)

Here is how I am getting the roles:

   public ActionResult AdminRolesAndAccessRules()
   {
        String[] rolesArray;
        rolesArray = Roles.GetAllRoles();

        ViewBag.roles = rolesArray;

        return PartialView();
    }

and here is how I am using the information:

<div class="scroller">
    <table>
        @foreach (MembershipUserCollection muc in ViewBag.roles)
    {                                        
        if(column == 1) {
            classe = "whiteRow";
            column = 0;
        }
        else {
            classe = "grayRow";
            column = 1;
        }
    <tr class="@classe"> 
        <td class="adminSetFormRowUsuario">role</td> 
        <td class="adminSetFormRowGrupo"></td> 
        <td class="formAction centerAlign">
            <img src="~/Images/editar.gif" alt="Editar"/>
            <span style="margin-left:5px"></span>
            <a href='javascript:AjaxRemoveUser("/Account/DeleteUser?role=@muc", "POST", "DinamicContent", "AdminSettingsTabsStructure")'><img src="~/Images/excluir.gif" alt="Excluir"/></a>
        </td> 
    </tr>

    }     
    </table>

Debugging I can see 2 values in ViewBag.roles but still the system complaining about a Null or not instantiated object.

Answer 1

// string array being assigned here
String[] rolesArray = Roles.GetAllRoles();
ViewBag.roles = rolesArray;

Debbugging I can see 2 values in ViewBag.rules but still the system
complaining about a Null or not instatiated object.

Those 2 values are presumably the roles you assigned.

// This looks wrong...you are treating each string in the array as MembershipUserCollection
@foreach (MembershipUserCollection muc in ViewBag.roles)
{
}

// instead, this should give you the role names
@foreach( string role in ViewBag.roles )
{
    <div>@role</div>
}