Fragment切换时更换Menu

如题，我希望实现在切换Fragment时更换Menu，用到了Activity的invalidateOptionsMenu()方法，该方法顾名思义

贴两段代码：

@Override
    public boolean onCreateOptionsMenu(Menu menu){
        menuInflater= getMenuInflater();
        if(cur == 1){
            menuInflater.inflate(R.menu.menu_main, menu);
        }else{
            menuInflater.inflate(R.menu.menu_com, menu);
        }
        return super.onCreateOptionsMenu(menu);
    }

if(f==1){
            cur = 1;
            mFragmentManager.beginTransaction().replace(R.id.main_container_layout, groupFragment).commit();
            invalidateOptionsMenu();
            changeStyle(bottom_group);
        }else if(f==2){
            cur = 2;
            mFragmentManager.beginTransaction().replace(R.id.main_container_layout, qaFragment).commit();
            invalidateOptionsMenu();
            changeStyle(bottom_qa);
        }