Fragment里更改Activity ToolBar菜单

public class BaseFragment extends Fragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //来指出fragment愿意添加item到选项菜单(否则, fragment将接收不到对 onCreateOptionsMenu()的调用)
        setHasOptionsMenu(true);
    }

//重新加载toolbar上的布局menu_home
@Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        mThis.getMenuInflater().inflate(R.menu.menu_home, menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_item_home:
                ((MainActivity)mThis).selectItem(1);
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}