如何设置一个主 activity 并在 android 中填充片段

Question

我有一个 mainactivity 和其他片段，我想要的是通过只使用那个 activity ，我在 activity 中显示一个默认片段然后当用户点击在导航抽屉上，然后根据该项目的片段必须填充在相同的区域但具有不同的信息，我已经搜索了很多但没有找到合适的解决方案，我在这里粘贴我的 mainactivity class ，

public class MainActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener, FragmentOne.OnFragmentInteractionListener,
FragmentTwo.OnFragmentInteractionListener {

    private ListView mDrawerList;
    private String[] mNavigationDrawerItemTitles;
    Toolbar toolbar;

    private SliderLayout mDemoSlider;

    DrawerLayout drawer;
    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        mTitle = mDrawerTitle = getTitle();
        setSupportActionBar(toolbar);
  drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
       NavigationView navView = (NavigationView) findViewById(R.id.nav_right_view);
navView.setNavigationItemSelectedListener(this);

navView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(MenuItem item) {
                    // Handle Right navigation view item clicks here.
                    int id = item.getItemId();
                    Fragment fragment = null;
                    Class fragmentClass = null;


                if (id == R.id.nav_settings) {
                    fragmentClass = first.class;

                } else if (id == R.id.nav_logout) {
                    fragmentClass = secnd.class;

                }    try {
                    fragment = (Fragment) fragmentClass.newInstance();
                } catch (Exception e) {
                    e.printStackTrace();
                }



                FragmentManager fragmentManager = getSupportFragmentManager();
                fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
                item.setChecked(true);

                setTitle(item.getTitle());

                DrawerLayout mDrawer = (DrawerLayout) findViewById(R.id.drawer_layout);
                mDrawer.closeDrawers();
                return true;
            }
        });
    }

第一个片段的代码 class 在这里，

public class first extends Fragment {

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";


    private String mParam1;
    private String mParam2;

    private OnFragmentInteractionListener mListener;

    public first() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment FragmentOne.
     */
    // TODO: Rename and change types and number of parameters
    public static first newInstance(String param1, String param2) {
        FragmentOne fragment = new FragmentOne();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_fragment_one, container, false);
    }

    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p/>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }
}

提前致谢

Answer 1

为了解决您的问题，我只是使用您的代码并做了一些改进，只需在您的 activity 文件中使用所需的代码。

   protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        mTitle = mDrawerTitle = getTitle();
        setSupportActionBar(toolbar);
///it is required code
    if (savedInstanceState == null) {
        Fragment fragment = null;
        Class fragmentClass = null;
        fragment = new Fragmentforslider();
      fragmentClass= FragmentOne.class;
        try {

        } catch (Exception e) {
            e.printStackTrace();
        }

        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
    }

    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);