Android How to enable and disable Action bar button

MenuOverride 

@Overridepublic boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.    getMenuInflater().inflate(R.menu.menu_next, menu);

    if (!check)
    {

        MenuItem item = menu.findItem(R.id.menu_next);
        item.setVisible(false);
        invalidateOptionsMenu();
    }
    else if(check)
    {
        MenuItem item = menu.findItem(R.id.menu_next);
        item.setVisible(true);
        invalidateOptionsMenu();
    }
    return true;
}

Void Function()

{

Do what you want 

call==>

check=true;
invalidateOptionsMenu();

}