如何在导航视图中添加列表选择项

Question

如何在导航视图中添加带有项目的列表，我需要一个列表项目隐藏在导航视图中，用户可以在单击时单击项目，列表显示单击项目下方的项目，下一个示例如何：

Answer 1

您可以像 this 示例中那样进行操作。我在这里添加了代码只是为了有一个完整的例子。

首先你需要添加一个自定义适配器：

public class CustomExpandableListAdapter extends BaseExpandableListAdapter {

    private Context mContext;
    private List<String> mExpandableListTitle;
    private Map<String, List<String>> mExpandableListDetail;
    private LayoutInflater mLayoutInflater;

    public CustomExpandableListAdapter(Context context, List<String> expandableListTitle,
                                       Map<String, List<String>> expandableListDetail) {
        mContext = context;
        mExpandableListTitle = expandableListTitle;
        mExpandableListDetail = expandableListDetail;
        mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public Object getChild(int listPosition, int expandedListPosition) {
        return mExpandableListDetail.get(mExpandableListTitle.get(listPosition))
            .get(expandedListPosition);
    }

    @Override
    public long getChildId(int listPosition, int expandedListPosition) {
        return expandedListPosition;
    }

    @Override
    public View getChildView(int listPosition, final int expandedListPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {
        final String expandedListText = (String) getChild(listPosition, expandedListPosition);
        if (convertView == null) {
            convertView = mLayoutInflater.inflate(R.layout.list_item, null);
        }
        TextView expandedListTextView = (TextView) convertView
            .findViewById(R.id.expandedListItem);
        expandedListTextView.setText(expandedListText);
        return convertView;
    }

    @Override
    public int getChildrenCount(int listPosition) {
        return mExpandableListDetail.get(mExpandableListTitle.get(listPosition))
            .size();
    }

    @Override
    public Object getGroup(int listPosition) {
        return mExpandableListTitle.get(listPosition);
    }

    @Override
    public int getGroupCount() {
        return mExpandableListTitle.size();
    }

    @Override
    public long getGroupId(int listPosition) {
        return listPosition;
    }

    @Override
    public View getGroupView(int listPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        String listTitle = (String) getGroup(listPosition);
        if (convertView == null) {
            convertView = mLayoutInflater.inflate(R.layout.list_group, null);
        }
        TextView listTitleTextView = (TextView) convertView
            .findViewById(R.id.listTitle);
        listTitleTextView.setTypeface(null, Typeface.BOLD);
        listTitleTextView.setText(listTitle);
        return convertView;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public boolean isChildSelectable(int listPosition, int expandedListPosition) {
        return true;
    }
}

然后你可以为你的列表添加一个来源：

public class ExpandableListDataSource {

    /**
     * Returns fake data of films
     *
     * @param context
     * @return
     */
    public static Map<String, List<String>> getData(Context context) {
        Map<String, List<String>> expandableListData = new TreeMap<>();

        List<String> filmGenres = Arrays.asList(context.getResources().getStringArray(R.array.film_genre));

        List<String> actionFilms = Arrays.asList(context.getResources().getStringArray(R.array.actionFilms));
        List<String> musicalFilms = Arrays.asList(context.getResources().getStringArray(R.array.musicals));
        List<String> dramaFilms = Arrays.asList(context.getResources().getStringArray(R.array.dramas));
        List<String> thrillerFilms = Arrays.asList(context.getResources().getStringArray(R.array.thrillers));
        List<String> comedyFilms = Arrays.asList(context.getResources().getStringArray(R.array.comedies));

        expandableListData.put(filmGenres.get(0), actionFilms);
        expandableListData.put(filmGenres.get(1), musicalFilms);
        expandableListData.put(filmGenres.get(2), dramaFilms);
        expandableListData.put(filmGenres.get(3), thrillerFilms);
        expandableListData.put(filmGenres.get(4), comedyFilms);

        return expandableListData;
    }
}

它从 string.xml 中获取数据：

<resources>
    <string name="app_name">ExpandableNavigationDrawer</string>
    <string name="action_settings">Settings</string>
    <string name="drawer_open">Open navigation drawer</string>
    <string name="drawer_close">Close navigation drawer</string>
    <string name="film_genres">Film genres</string>
    <string name="website">https://en.wikipedia.org/wiki/Film</string>
    <string name="date">22 Oct 2015</string>
    <string name="selected_item">Selected item</string>

    <string-array name="film_genre">
        <item>Action</item>
        <item>Musical</item>
        <item>Drama</item>
        <item>Thriller</item>
        <item>Comedy</item>
    </string-array>

    <string-array name="actionFilms">
        <item>Dr. No (1962)</item>
        <item>Goldfinger (1964)</item>
        <item>Thunderball (1965)</item>
        <item>Live and Let Die (1973)</item>
        <item>Moonraker (1979)</item>
        <item>For Your Eyes Only (1981)</item>
        <item>Octopussy (1983)</item>
        <item>A View to a Kill (1985)</item>
        <item>Licence to Kill (1989)</item>
        <item>GoldenEye (1995)</item>
    </string-array>

    <string-array name="musicals">
        <item>Naughty Marietta (1935)</item>
        <item>Rose Marie (1936)</item>
        <item>Maytime (1937)</item>
        <item>Sweethearts (1938)</item>
        <item>Bitter Sweet (1940)</item>
        <item>New Moon (1940)</item>
        <item>I Married an Angel (1942)</item>
        <item>Lady Be Good (1941)</item>
        <item>Ship Ahoy (1942)</item>
        <item>Sensations of 1945 (1944)</item>
    </string-array>

    <string-array name="dramas">
        <item>Home of the Brave (1949)</item>
        <item>The Accused (1949)</item>
        <item>12 Angry Men (1957)</item>
        <item>Compulsion (1959)</item>
        <item>Inherit the Wind (1960)</item>
        <item>To Kill a Mockingbird (1962)</item>
        <item>Mrs. Miniver (1942)</item>
        <item>Since You Went Away (1944)</item>
        <item>The Champ (1931)</item>
        <item>Nashville (1975)</item>
    </string-array>

    <string-array name="thrillers">
        <item>Alien (1979)</item>
        <item>The French Connection (1971)</item>
        <item>High Noon (1952)</item>
        <item>Double Indemnity (1944)</item>
        <item>Safety Last (1923)</item>
        <item>The Lady From Shanghai (1948)</item>
        <item>The Third Man (1949)</item>
        <item>Rear Window (1954)</item>
        <item>The 39 Steps (1935)</item>
        <item>Shadow of a Doubt (1943)</item>
    </string-array>

    <string-array name="comedies">
        <item>Safety Last (1923)</item>
        <item>Duck Soup (1933)</item>
        <item>Cat Ballou (1965)</item>
        <item>What\'s Up, Tiger Lily? (1966)</item>
        <item>Blazing Saddles (1974)</item>
        <item>Play It Again, Sam (1972)</item>
        <item>The Cheap Detective (1978)</item>
        <item>The Naked Gun (1988)</item>
        <item>The Freshman (1990)</item>
        <item>Waiting for Guffman (1996) </item>
    </string-array>

</resources>

然后你可以将它添加到你的 MainActivity：

public class MainActivity extends ActionBarActivity {

    private DrawerLayout mDrawerLayout;
    private ActionBarDrawerToggle mDrawerToggle;
    private String mActivityTitle;

    private ExpandableListView mExpandableListView;
    private ExpandableListAdapter mExpandableListAdapter;
    private List<String> mExpandableListTitle;
    private Map<String, List<String>> mExpandableListData;
    private TextView mSelectedItemView;

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

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mActivityTitle = getTitle().toString();

        mExpandableListView = (ExpandableListView) findViewById(R.id.navList);
        mSelectedItemView = (TextView) findViewById(R.id.selected_item);

        LayoutInflater inflater = getLayoutInflater();
        View listHeaderView = inflater.inflate(R.layout.nav_header, null, false);
        mExpandableListView.addHeaderView(listHeaderView);

        mExpandableListData = ExpandableListDataSource.getData(this);
        mExpandableListTitle = new ArrayList(mExpandableListData.keySet());

        addDrawerItems();
        setupDrawer();

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);
    }

    private void addDrawerItems() {
        mExpandableListAdapter = new CustomExpandableListAdapter(this, mExpandableListTitle, mExpandableListData);
        mExpandableListView.setAdapter(mExpandableListAdapter);
        mExpandableListView.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {
            @Override
            public void onGroupExpand(int groupPosition) {
                getSupportActionBar().setTitle(mExpandableListTitle.get(groupPosition).toString());
                mSelectedItemView.setText(mExpandableListTitle.get(groupPosition).toString());
            }
        });

        mExpandableListView.setOnGroupCollapseListener(new ExpandableListView.OnGroupCollapseListener() {
            @Override
            public void onGroupCollapse(int groupPosition) {
                getSupportActionBar().setTitle(R.string.film_genres);
                mSelectedItemView.setText(R.string.selected_item);
            }
        });

        mExpandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v,
                                        int groupPosition, int childPosition, long id) {
                String selectedItem = ((List) (mExpandableListData.get(mExpandableListTitle.get(groupPosition))))
                    .get(childPosition).toString();
                getSupportActionBar().setTitle(selectedItem);
                mSelectedItemView.setText(mExpandableListTitle.get(groupPosition).toString() + " -> " + selectedItem);
                mDrawerLayout.closeDrawer(GravityCompat.START);
                return false;
            }
        });
    }

    private void setupDrawer() {
        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.drawer_open, R.string.drawer_close) {

            /** Called when a drawer has settled in a completely open state. */
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                getSupportActionBar().setTitle(R.string.film_genres);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            /** Called when a drawer has settled in a completely closed state. */
            public void onDrawerClosed(View view) {
                super.onDrawerClosed(view);
                getSupportActionBar().setTitle(mActivityTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };

        mDrawerToggle.setDrawerIndicatorEnabled(true);
        mDrawerLayout.setDrawerListener(mDrawerToggle);
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        // Sync the toggle state after onRestoreInstanceState has occurred.
        mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @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();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        // Activate the navigation drawer toggle
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

您也可以尝试不同的方法：使用名为Material Drawer的第三方库。在文档和代码中，您可以阅读如何实现可折叠菜单。您也可以参考Google Play 商店中提供的示例应用程序。