android - how to get the action bar button? findviewbyid seems doesn't work -

suppose have 2 buttons, 1 action button in action bar(@+id/button1). , common button in layout(@+id/button2).

how can set button1 disabled when click button2?

findviewbyid(button1) seems not work. return null.

this menu xml:

<menu xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <item android:id="@+id/button1" android:title="submit" android:showasaction="always" /> </menu>

and mainacticity:

@override public boolean oncreateoptionsmenu(menu menu) {     menuinflater inflater = getmenuinflater();     inflater.inflate(r.menu.my, menu);     return true; } @override public boolean onoptionsitemselected(menuitem item) {     int id = item.getitemid();     if (id == r.id.button1 ) {         return true;     }     return super.onoptionsitemselected(item); } @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_my);     button1 = (button) findviewbyid(r.id.button1);/*which return null*/     button2 = (button) findviewbyid(r.id.button2);     button2.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {             button1.setenabled(false);/*what failed do*/         }     }); } 

1.create variable menuitem in activity class

    menuitem menuitem; 

2. find variable in oncreateoptionsmenu

    @override         public boolean oncreateoptionsmenu(menu menu) {             getmenuinflater().inflate(r.menu.menu_main, menu);             menuitem = menu.finditem(r.id.item_circuit);             return super.oncreateoptionsmenu(menu);         } 

3. disable item in buttonclick method

    button2.setonclicklistener(new view.onclicklistener() {                 @override                 public void onclick(view v) {                     menuitem.setenabled(false);                 }             });