java - Android - 如何更改抽屉导航中的 fragment

Question

我对 Android 编程还很陌生，但到目前为止我的表现还不错。我已经阅读了很多关于这个问题的答案，但似乎无法让我的工作。基本上我所拥有的是一个带有抽屉导航的 MainActivity。我有两个 fragment 使用相应的 fragment 布局 xml 正确初始化。目前我可以在应用程序启动时显示我的第一个 fragment ，当我点击抽屉中的每个项目时，标题会发生变化；但是， fragment 保持不变。有什么建议么？我认为相关的代码如下(未显示的是 NavigationDrawerFragment.java 的代码以及 Eclipse 自动构建的必要代码)。提前致谢!

public class MainActivity extends Activity
implements NavigationDrawerFragment.NavigationDrawerCallbacks {

/**
 * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
 */
private NavigationDrawerFragment mNavigationDrawerFragment;

/**
 * Used to store the last screen title. For use in {@link #restoreActionBar()}.
 */
private CharSequence mTitle;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mNavigationDrawerFragment = (NavigationDrawerFragment)
            getFragmentManager().findFragmentById(R.id.navigation_drawer);
    mTitle = getTitle();

    // Set up the drawer.
    mNavigationDrawerFragment.setUp(
            R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));


}

@Override
public void onNavigationDrawerItemSelected(int position) {
    // update the main content by replacing fragments

    FragmentManager fragmentManager = getFragmentManager();
    fragmentManager.beginTransaction()
            .replace(R.id.content_frame, PlaceholderFragment.newInstance(position + 1))
            .commit();

}

public void onSectionAttached(int number) {
    switch (number) {
        case 1:
            mTitle = getString(R.string.title_home);
            break;
        case 2:
            mTitle = getString(R.string.title_infodirect);
            break;
        case 3:
            mTitle = getString(R.string.title_trailmap);
            break;
        case 4:
            mTitle = getString(R.string.title_poi);
            break;
        case 5:
            mTitle = getString(R.string.title_photomap);
            break;
        case 6:
            mTitle = getString(R.string.title_report);
            break;
        case 7:
            mTitle = getString(R.string.title_rulesreg);

    }
}

public void restoreActionBar() {
    ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
    actionBar.setDisplayShowTitleEnabled(true);
    actionBar.setTitle(mTitle);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    if (!mNavigationDrawerFragment.isDrawerOpen()) {
        // Only show items in the action bar relevant to this screen
        // if the drawer is not showing. Otherwise, let the drawer
        // decide what to show in the action bar.
        getMenuInflater().inflate(R.menu.overview, menu);
        restoreActionBar();
        return true;
    }
    return super.onCreateOptionsMenu(menu);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    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;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_home, container, false);
        return rootView;
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        ((MainActivity) activity).onSectionAttached(
                getArguments().getInt(ARG_SECTION_NUMBER));
    }
}

public static class InfoDirectFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static InfoDirectFragment newInstance(int sectionNumber) {
        InfoDirectFragment fragment = new InfoDirectFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public InfoDirectFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_infodirect, container, false);
        return rootView;
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        ((MainActivity) activity).onSectionAttached(
                getArguments().getInt(ARG_SECTION_NUMBER));
    }
}
}

Answer 1

关注 link!!了解更多详情并使用

private class DrawerItemClickListener implements
            ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            selectItem(position);
        }
    }

和

private void selectItem(int position) {
    FragmentManager fragmentManager = getSupportFragmentManager();
    FragmentTransaction ft = fragmentManager.beginTransaction();


    switch (position) {

    case 0:

        ft.replace(R.id.content_frame, new Fragment1, Constants.TAG_FRAGMENT).commit();

        break;


    case 1:
        ft.replace(R.id.content_frame, new Fragment2, Constants.TAG_FRAGMENT);

        ft.commit();
        break;

    }

    mDrawerList.setItemChecked(position, true);
    setTitle(title[position]);

    // Close drawer
    mDrawerLayout.closeDrawer(mDrawerList);
}