How to assign roles to users by a single user

Question

I have been struggling to assign roles to users by a single person on ASP.NET MVC. I have used a view bag on a controller and a dropdown list on the view. When I assign roles, it is not saved on the database. Can anyone help me sort this out? The error message which I get is "UserId and RoleId are required."

 

/* This is the AssignRole View */

@model Microsoft.AspNet.Identity.EntityFramework.IdentityUserRole

@{

ViewBag.Title = "AssignRole";

}

<h2>AssignRole</h2>

@using (Html.BeginForm())

{

<div class="form-horizontal">

<h4>Assign Roles</h4>

<hr />

<div class="form-group">

@Html.LabelFor(model => model.UserId, "User Name", new { @class = "col-md-2 control-label" }) <!--User name is label-->

<div class="col-md-10">

@Html.DropDownList("AllUsers", null, "Select a User", new { @class = "form-control" })

@Html.ValidationMessageFor(model => model.UserId, "", new { @class = "text-danger" })

</div>

</div>

<div class="form-group">

@Html.LabelFor(model => model.RoleId, "Role Type", new { @class = "col-md-2 control-label" })

<div class="col-md-10"> <!--Role Type is label-->

@Html.DropDownList("AllRoles", null, "Select a Role", new { @class = "form-control" })

@Html.ValidationMessageFor(model => model.RoleId, "", new { @class = "text-danger" })

</div>

</div>

<div class="form-group">

<div class="col-md-offset-2 col-md-10">

<input type="submit" value="Assign" class="btn btn-default" />

</div>

</div>

</div>

}

<div>

@Html.ActionLink("Back to List", "Index")

</div>

/* This is Roles Controller */

// Assign roles

public ActionResult AssignRole()

{

ViewBag.AllUsers = new SelectList(db.Users, "Id", "UserName");

ViewBag.AllRoles = new SelectList(db.Roles, "Id", "Name");

return View();

}

[HttpPost]

public ActionResult AssignRole(IdentityUserRole userRole)

{

if (ModelState.IsValid)

{

db.UserRoles.Add(userRole);

try

{

db.SaveChanges();

}

catch (DbEntityValidationException e)

{

Console.WriteLine(e);

}

return RedirectToAction("UsersWithRoles");

}

ViewBag.AllUsers = new SelectList(db.Users, "Id", "UserName",userRole.UserId);

ViewBag.AllRoles = new SelectList(db.Roles, "Id", "Name",userRole.RoleId);

return View(userRole);

}