java - 抽屉导航未显示？

Question

这个问题已经存在:

navigation drawer not showing properly

已关闭 4 年前。

您好，我正在使用抽屉导航开发新闻应用程序，但它不显示导航，仅显示一个 fragment ，我按照此 tutorial 进行操作。

screenshot of app

位于 MainActivity.java 文件下方

public class MainActivity extends AppCompatActivity {
    private DrawerLayout mDrawer;
    private Toolbar toolbar;
    private   NavigationView nvDrawer;
    private ActionBarDrawerToggle drawerToggle;

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

        // Set a Toolbar to replace the ActionBar.
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        // Find our drawer view
        mDrawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawerToggle = setupDrawerToggle();

        // Tie DrawerLayout events to the ActionBarToggle
        mDrawer.addDrawerListener(drawerToggle);

        nvDrawer = (NavigationView) findViewById(R.id.nvView);

// Inflate the header view at runtime
        View headerLayout = nvDrawer.inflateHeaderView(R.layout.nav_header);
// We can now look up items within the header if needed
        ImageView ivHeaderPhoto = (ImageView) headerLayout.findViewById((R.id.header_image));
        setupDrawerContent(nvDrawer);
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.flContent, new BBCSportFragment()).commit();
        fragmentManager.beginTransaction().replace(R.id.flContent, new FoxSportsFragment()).commit();
        fragmentManager.beginTransaction().replace(R.id.flContent, new TalkSportsFragment()).commit();

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // The action bar home/up action should open or close the drawer.
        switch (item.getItemId()) {
            case android.R.id.home:
                mDrawer.openDrawer(GravityCompat.START);
                return true;
        }

        return super.onOptionsItemSelected(item);
    }

    private void setupDrawerContent(NavigationView navigationView) {
        navigationView.setNavigationItemSelectedListener(
                menuItem -> {
                    selectDrawerItem(menuItem);
                    return true;
                });
    }

    public void selectDrawerItem(MenuItem menuItem) {
        // Create a new fragment and specify the fragment to show based on nav item clicked
        Fragment fragment = null;
        Class fragmentClass = null;
        switch (menuItem.getItemId()) {
            case R.id.bbcsports_fragment:
                fragmentClass = BBCSportFragment.class;
                break;
            case R.id.talksports_fragment:
                fragmentClass = TalkSportsFragment.class;
                break;
            case R.id.foxsports_fragment:
                fragmentClass = FoxSportsFragment.class;
                break;
            default:

        }

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

        // Insert the fragment by replacing any existing fragment

        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.flContent, fragment).commit();
        // Highlight the selected item has been done by NavigationView
        menuItem.setChecked(true);
        // Set action bar title
        setTitle(menuItem.getTitle());
        // Close the navigation drawer
        mDrawer.closeDrawers();
    }

    private ActionBarDrawerToggle setupDrawerToggle() {
        // NOTE: Make sure you pass in a valid toolbar reference.  ActionBarDrawToggle() does not require it
        // and will not render the hamburger icon without it.
        return new ActionBarDrawerToggle(this, mDrawer, toolbar, R.string.drawer_open,  R.string.drawer_close);
    }

}

在activity_main.xml下面，我实现了抽屉导航以及抽屉布局。

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- This LinearLayout represents the contents of the screen  -->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <!-- The ActionBar displayed at the top -->
        <include
            layout="@layout/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <!-- The main content view where fragments are loaded -->
        <FrameLayout
            android:id="@+id/flContent"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior" />
    </LinearLayout>

    <!-- The navigation drawer that comes from the left -->
    <!-- Note that `android:layout_gravity` needs to be set to 'start' -->
    <android.support.design.widget.NavigationView
        android:id="@+id/nvView"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:background="@android:color/white"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/navigation_menu" />

</android.support.v4.widget.DrawerLayout>

在 BBCFragment.java 下

public class BBCSportFragment extends Fragment {

    public List<Article> articleList = new ArrayList<Article>();
    @BindView(R.id.recycler_view)
    RecyclerView recyclerView;
    private SportNews sportNews;
    private ArticleAdapter articleAdapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_bbcsport, container, false);
        ButterKnife.bind(this, view);
        SportInterface sportInterface = SportClient.getApiService();
        Call<SportNews> call = sportInterface.getArticles();
        call.enqueue(new Callback<SportNews>() {
            @Override
            public void onResponse(Call<SportNews> call, Response<SportNews> response) {
                sportNews = response.body();
                if (sportNews != null && sportNews.getArticles() != null) {
                    articleList.addAll(sportNews.getArticles());
                }
                articleAdapter = new ArticleAdapter(articleList, sportNews);
                RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getContext());
                recyclerView.setLayoutManager(layoutManager);
                recyclerView.setAdapter(articleAdapter);
            }

            @Override
            public void onFailure(Call<SportNews> call, Throwable t) {

            }
        });


        return view;


    }
}

位于 bbc_fragment.xml 下方

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <!-- The main content view -->
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <!-- Put what you want as your normal screen in here, you can also choose for a linear layout or any other layout, whatever you

prefer -->

Answer 1

您应该重写onPostCreate并像这样同步切换抽屉状态

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

然后您覆盖onConfigurationChanged并更改切换抽屉配置

@Override
public void onConfigurationChanged(Configuration newConfig) {
  super.onConfigurationChanged(newConfig);
  // Pass any configuration change to the drawer toggles
  drawerToggle.onConfigurationChanged(newConfig);
}

添加这两个方法就可以了。