无法更改此布局格式的字段值？

Question

我有3个布局MainActivity.java（AppCompatActivity）AssignmentActivity.java（Fragment）DataFragment.java（Fragment）

在MainActivity.java的导航抽屉上，我使用以下代码显示AssignmentActivity- Fragment：

MainActivity.java

private void displaySelectedScreen(int itemId) {

    Fragment fragment = null;
    switch (itemId) {            
        case R.id.nav_assign_tags:
            fragment= new TagAssignmentActivity();
            break;            
    }

    //Replacing the fragment
    if (fragment != null) {
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.replace(R.id.content_frame, fragment);
        ft.commit();
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    assert drawer != null;
    drawer.closeDrawer(GravityCompat.START);
}

AssignmentActivity.java

public class AssignmentActivity extends Fragment {

    private SectionsPagerAdapter mSectionsPagerAdapter;
    private ViewPager mViewPager;

      @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        getActivity().setTitle("");

        mSectionsPagerAdapter = new SectionsPagerAdapter(getActivity().getSupportFragmentManager());

        mViewPager = (ViewPager) getActivity().findViewById(R.id.container);
        mViewPager.setAdapter(mSectionsPagerAdapter);

        TabLayout tabLayout = (TabLayout) getActivity().findViewById(R.id.tabs);
        tabLayout.setupWithViewPager(mViewPager);

    }


}

    public static class PlaceholderFragment extends Fragment {
        private static final String ARG_SECTION_NUMBER = "section_number";

        public PlaceholderFragment() {
        }

        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_tag_assignment, container, false);
            TextView textView = (TextView) rootView.findViewById(R.id.section_label);
            textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
            return rootView;
        }
    }

    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            switch (position) {
                case 0:
                    return new DataFragment();
                case 1:
                    return new PhotoFragment();
            }
            return null;
        }

        @Override
        public int getCount() {
            return 2;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            switch (position) {
                case 0:
                    return "Data";
                case 1:
                    return "Photos";
            }
            return null;
        }
    }

DataFragment.java

public class DataFragment extends Fragment {

    View rootView;
    EditText serialNoField;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        rootView = inflater.inflate(R.layout.tag_data_fragment , container, false);
        return rootView;
    }
}

tag_data_fragment.xml

<AutoCompleteTextView
        android:id="@+id/type"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:hint="@string/txt_asset_type"
        android:textSize="15sp" />

我想在AssignmentActivity.java中更改tag_data_fragment.xml上的type值。

我试过给布局充气但是失败了。

我如何实现它？