c# - Adding role with UserManager -

i trying build simple method (just test how works), grant me (current user) new role (i have 1 role now, can simple query)

public actionresult index() {     using (var db = new mydbcontext())     {         var manager = new usermanager<applicationuser>(new userstore<applicationuser>(db));         var id = user.identity.getuserid();         var role = db.aspnetroles.first();         manager.addtorole(id, role.name);     }      return view(); } 

i getting error: the entity type applicationuser not part of model current context. on manager.addtorole(id, role.name); line. novice asp.net don't know infrastructure, code mentioned lot of times (here, on stack) in questions user registration.

by way, goal, have implement role system project database-first migration system, manager.addtorole(id, role.name); code add records in db?

below stub (incomplete), shows adding newly created user role:

            dbcontext context = db;             identityresult ir;             var um = new usermanager<applicationuser>(                 new userstore<applicationuser>(context));              applicationuser au = new applicationuser();             au = db.users.firstordefault(u => u.username == uname);              if (au == null)             {                 // add user                 var user = new applicationuser()                 {                     username = trustnoone("name", uname),                     email = trustnoone("email", uemail),                     properusername = trustnoone("propername", upropname)                 };                  // create password user                 ir = um.create(user, upass);                  // assign user role                 if (user.isinrole(urole) != true)                 {                     ir = um.addtorole(user.id, urole);                 }             } 

please note, uname, uemail, upropname, upass, , urole parameters passed method code lives. also, can ignore trustnoone bit (it's use).