android - cast a class to an activity -

i'm trying create listview wich enable open 2 other activities created before. i've got problem intent. i'm quite sure understand lactivity activity wich exists. explain me why?

thank you!!

public listmenu extends activity {   private listview malistview;   @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.list);      // create list of elements     list<elementofconstruction> liste = new arraylist<elementofconstruction>();      string columns = null;     class<?> calculcolumns = null;     elementofconstruction columns = new elementofconstruction(columns, 0, r.drawable.columns, calculcolumns, 100);     liste.add(columns);     string beam1 = null;     class<?> calculbeam = null;     elementofconstruction beam1 = new elementofconstruction(beam1, 0, r.drawable.beam1, calculbeam, 200);      //récupération de la listview créée dans le fichier main.xml       malistview = (listview) findviewbyid(r.id.malistview);      arrayadapter<elementofconstruction> adapter = new arrayadapter<elementofconstruction>(listmenu.this,             r.layout.row_list, r.id.name, liste);      // affecter l'adapter à notre listview     malistview.setadapter(adapter);      malistview.setonitemclicklistener(new onitemclicklistener() {          @override         public void onitemclick(adapterview<?> parent, view view,                 int position, long id) {              //on récupère le titre de l'item dans un elementofconstruction               //start new activity             //récupération de l’item sélectionné             elementofconstruction element = (elementofconstruction)malistview.getadapter().getitem(position);              class<?> lactivity = element.getactivity();             int numidentification = element.getnumidentification();              //open new activity             intent intent = new intent(listmenu.this, lactivity.class);             startactivityforresult(intent,numidentification);            }     });  }} 

you passing class of activity intent, not activity itself.

change line:

class<?> lactivity = element.getactivity(); 

to:

activity lactivity = element.getactivity();