Google 将工具栏添加到导航抽屉示例 - 带有测试代码和屏幕截图

Question

我正在尝试通过 Google 将工具栏和右侧抽屉添加到众所周知的 Navigation Drawer Example，但由于某些原因，工具栏不可见：

我的完整项目是 available at GitHub。

这是 XML 布局文件 activity_main.xml（我不使用 include 和一个单独的 toolbar.xml 文件 - 因为只有一个 Activity 在应用程序中）：

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

    <RelativeLayout 
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <android.support.v7.widget.Toolbar 
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#FFF"
        android:theme="@style/ThemeOverlay.AppCompat.Dark" />

    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    </RelativeLayout>

    <ListView
        android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#111"/>

    <ListView
        android:id="@+id/right_drawer"
        android:layout_width="180dp"
        android:layout_height="match_parent"
        android:layout_gravity="end"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#CCC"/>
</android.support.v4.widget.DrawerLayout>

这是添加了 mToolbar 和 mActionList 的 MainActivity.java：

public class MainActivity extends AppCompatActivity {
    private Toolbar mToolbar;
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ListView mActionList;
    private ActionBarDrawerToggle mDrawerToggle;

    private String[] mPlanetTitles;
    private String[] mActions;
    private TypedArray mIcons;

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

        mPlanetTitles = getResources().getStringArray(R.array.planets_array);
        mActions = getResources().getStringArray(R.array.music_actions);
        mIcons = getResources().obtainTypedArray(R.array.music_icons);

        mToolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);
        mActionList = (ListView) findViewById(R.id.right_drawer);

        mDrawerList.setAdapter(new ArrayAdapter<String>(this, R.layout.drawer_list_item, mPlanetTitles) {
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                TextView view = (TextView) super.getView(position, convertView, parent);
                view.setCompoundDrawablePadding(16);
                view.setCompoundDrawablesWithIntrinsicBounds(R.drawable.ic_stars_white_24dp, 0, 0, 0);
                return view;
            }
        });

        mActionList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, mActions) {
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                TextView view = (TextView) super.getView(position, convertView, parent);
                view.setCompoundDrawablePadding(16);
                int res = mIcons.getResourceId(position, R.drawable.ic_menu_black_24dp);
                view.setCompoundDrawablesWithIntrinsicBounds(res, 0, 0, 0);
                return view;
            }
        });

        // enable ActionBar app icon to behave as action to toggle nav drawer
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);

        // ActionBarDrawerToggle ties together the the proper interactions
        // between the sliding drawer and the action bar app icon
        mDrawerToggle = new ActionBarDrawerToggle(
                this,                  /* host Activity */
                mDrawerLayout,         /* DrawerLayout object */
                mToolbar,
                R.string.drawer_open,  /* "open drawer" description for accessibility */
                R.string.drawer_close  /* "close drawer" description for accessibility */
                ) {
            public void onDrawerClosed(View view) {
                mToolbar.setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

            public void onDrawerOpened(View drawerView) {
                mToolbar.setTitle(mDrawerTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            selectItem(0);
        }
    }

请指教，这里缺少什么 - 为什么工具栏不可见？

Answer 1

您在 RelativeLayout 中添加了 Toolbar，需要指定其位置，否则 FrameLayout 将占据整个屏幕。只需在 FrameLayout 中添加 android:layout_below="@id/toolbar" 即可将 FrameLayout 定位在工具栏下方。

更正以下代码：

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

<android.support.v7.widget.Toolbar 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#FFF"
    android:theme="@style/ThemeOverlay.AppCompat.Dark" />

<FrameLayout
    android:id="@+id/content_frame"
    android:layout_below="@id/toolbar"    //added this
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

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

由于您只有 2 个视图需要垂直放置，因此您只需将 RelativeLayout 替换为垂直放置的 LinearLayout。