没有操作栏的 Android 导航抽屉

Question

我在 Android Studio 上创建了导航抽屉活动，但我的主题没有 ActionBar（由于设计原因，我正在使用 Toolbar 小部件），它拒绝工作，在这里给了我一个 java.lang.NullPointerException 点：

mDrawerListView.setAdapter(new ArrayAdapter<String>(
            getActionBar().getThemedContext(),
            android.R.layout.simple_list_item_activated_1,
            android.R.id.text1,
            new String[]{
                    getString(R.string.title_section1),
                    getString(R.string.title_section2),
                    getString(R.string.title_section3),
            }));

所以我尝试用其他上下文 getter 函数替换 getActionBar().getThemedContext()，但没有成功...

编辑： 根据要求： 堆栈跟踪：

10-13 15:15:16.054 15849-15849/? E/AndroidRuntime: FATAL EXCEPTION: main
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime: java.lang.RuntimeException: Unable to start activity ComponentInfo{br.net.beno.supercarrinho/br.net.beno.supercarrinho.AtividadePrincipal}: android.view.InflateException: Binary XML file line #19: Error inflating class fragment
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2255)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2309)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.access$700(ActivityThread.java:157)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1289)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:99)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:176)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5319)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:511)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:  Caused by: android.view.InflateException: Binary XML file line #19: Error inflating class fragment
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:710)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.rInflate(LayoutInflater.java:752)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:495)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:255)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at br.net.beno.supercarrinho.AtividadePrincipal.onCreate(AtividadePrincipal.java:52)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:5326)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2218)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2309) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.access$700(ActivityThread.java:157) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1289) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:99) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:176) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5319) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:511) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:  Caused by: java.lang.NullPointerException
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at br.net.beno.supercarrinho.NavigationDrawerFragment.onCreateView(NavigationDrawerFragment.java:100)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.Fragment.performCreateView(Fragment.java:1962)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:995)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1185)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1287)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.FragmentManagerImpl.onCreateView(FragmentManager.java:2243)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.FragmentController.onCreateView(FragmentController.java:111)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:278)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(BaseFragmentActivityHoneycomb.java:31)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:78)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:686)
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.rInflate(LayoutInflater.java:752) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:495) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:397) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.view.LayoutInflater.inflate(LayoutInflater.java:353) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:255) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at br.net.beno.supercarrinho.AtividadePrincipal.onCreate(AtividadePrincipal.java:52) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.Activity.performCreate(Activity.java:5326) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1097) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2218) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2309) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.access$700(ActivityThread.java:157) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1289) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:99) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:176) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5319) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at java.lang.reflect.Method.invokeNative(Native Method) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:511) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869) 
10-13 15:15:16.054 15849-15849/? E/AndroidRuntime:     at dalvik.system.NativeStart.main(Native Method) 

NavigationDrawerFragment.java：

package br.net.beno.supercarrinho;

import android.support.v7.app.AppCompatActivity;
import android.app.Activity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

/**
 * Fragment used for managing interactions for and presentation of a navigation drawer.
 * See the <a href="https://developer.android.com/design/patterns/navigation-drawer.html#Interaction">
 * design guidelines</a> for a complete explanation of the behaviors implemented here.
 */
public class NavigationDrawerFragment extends Fragment {

    /**
     * Remember the position of the selected item.
     */
    private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";

    /**
     * Per the design guidelines, you should show the drawer on launch until the user manually
     * expands it. This shared preference tracks this.
     */
    private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";

    /**
     * A pointer to the current callbacks instance (the Activity).
     */
    private NavigationDrawerCallbacks mCallbacks;

    /**
     * Helper component that ties the action bar to the navigation drawer.
     */
    private ActionBarDrawerToggle mDrawerToggle;

    private DrawerLayout mDrawerLayout;
    private ListView mDrawerListView;
    private View mFragmentContainerView;

    private int mCurrentSelectedPosition = 0;
    private boolean mFromSavedInstanceState;
    private boolean mUserLearnedDrawer;

    public NavigationDrawerFragment() {
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Read in the flag indicating whether or not the user has demonstrated awareness of the
        // drawer. See PREF_USER_LEARNED_DRAWER for details.
        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
        mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);

        if (savedInstanceState != null) {
            mCurrentSelectedPosition = savedInstanceState.getInt(STATE_SELECTED_POSITION);
            mFromSavedInstanceState = true;
        }

        // Select either the default item (0) or the last selected item.
        selectItem(mCurrentSelectedPosition);

    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        // Indicate that this fragment would like to influence the set of actions in the action bar.
        setHasOptionsMenu(true);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        mDrawerListView = (ListView) inflater.inflate(
                R.layout.fragment_navigation_drawer, container, false);
        mDrawerListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                selectItem(position);
            }
        });
        mDrawerListView.setAdapter(new ArrayAdapter<String>(
                getActionBar().getThemedContext(),
                android.R.layout.simple_list_item_activated_1,
                android.R.id.text1,
                new String[]{
                        getString(R.string.title_section1),
                        getString(R.string.title_section2),
                        getString(R.string.title_section3),
                }));
        mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
        return mDrawerListView;
    }

    public boolean isDrawerOpen() {
        return mDrawerLayout != null && mDrawerLayout.isDrawerOpen(mFragmentContainerView);
    }

    /**
     * Users of this fragment must call this method to set up the navigation drawer interactions.
     *
     * @param fragmentId   The android:id of this fragment in its activity's layout.
     * @param drawerLayout The DrawerLayout containing this fragment's UI.
     */
    public void setUp(int fragmentId, DrawerLayout drawerLayout) {
        mFragmentContainerView = getActivity().findViewById(fragmentId);
        mDrawerLayout = drawerLayout;

        // set a custom shadow that overlays the main content when the drawer opens
        mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);

        // set up the drawer's list view with items and click listener

        ActionBar actionBar = getActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setHomeButtonEnabled(true);

        // ActionBarDrawerToggle ties together the the proper interactions
        // between the navigation drawer and the action bar app icon.
        mDrawerToggle = new ActionBarDrawerToggle(
                getActivity(),                    /* host Activity */
                mDrawerLayout,                    /* DrawerLayout object */
                R.drawable.ic_drawer,             /* nav drawer image to replace 'Up' caret */
                R.string.navigation_drawer_open,  /* "open drawer" description for accessibility */
                R.string.navigation_drawer_close  /* "close drawer" description for accessibility */
        ) {
            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                if (!isAdded()) {
                    return;
                }

                getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
            }

            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                if (!isAdded()) {
                    return;
                }

                if (!mUserLearnedDrawer) {
                    // The user manually opened the drawer; store this flag to prevent auto-showing
                    // the navigation drawer automatically in the future.
                    mUserLearnedDrawer = true;
                    SharedPreferences sp = PreferenceManager
                            .getDefaultSharedPreferences(getActivity());
                    sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true).apply();
                }

                getActivity().supportInvalidateOptionsMenu(); // calls onPrepareOptionsMenu()
            }
        };

        // If the user hasn't 'learned' about the drawer, open it to introduce them to the drawer,
        // per the navigation drawer design guidelines.
        if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
            mDrawerLayout.openDrawer(mFragmentContainerView);
        }

        // Defer code dependent on restoration of previous instance state.
        mDrawerLayout.post(new Runnable() {
            @Override
            public void run() {
                mDrawerToggle.syncState();
            }
        });

        mDrawerLayout.setDrawerListener(mDrawerToggle);
    }

    private void selectItem(int position) {
        mCurrentSelectedPosition = position;
        if (mDrawerListView != null) {
            mDrawerListView.setItemChecked(position, true);
        }
        if (mDrawerLayout != null) {
            mDrawerLayout.closeDrawer(mFragmentContainerView);
        }
        if (mCallbacks != null) {
            mCallbacks.onNavigationDrawerItemSelected(position);
        }
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            mCallbacks = (NavigationDrawerCallbacks) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException("Activity must implement NavigationDrawerCallbacks.");
        }
    }

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

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        // Forward the new configuration the drawer toggle component.
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        // If the drawer is open, show the global app actions in the action bar. See also
        // showGlobalContextActionBar, which controls the top-left area of the action bar.
        if (mDrawerLayout != null && isDrawerOpen()) {
            inflater.inflate(R.menu.global, menu);
            showGlobalContextActionBar();
        }
        super.onCreateOptionsMenu(menu, inflater);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }

        if (item.getItemId() == R.id.action_example) {
            Toast.makeText(getActivity(), "Example action.", Toast.LENGTH_SHORT).show();
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    /**
     * Per the navigation drawer design guidelines, updates the action bar to show the global app
     * 'context', rather than just what's in the current screen.
     */
    private void showGlobalContextActionBar() {
        ActionBar actionBar = getActionBar();
        actionBar.setDisplayShowTitleEnabled(true);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setTitle(R.string.app_name);
    }

    private ActionBar getActionBar() {
        return ((AppCompatActivity) getActivity()).getSupportActionBar();
    }

    /**
     * Callbacks interface that all activities using this fragment must implement.
     */
    public static interface NavigationDrawerCallbacks {
        /**
         * Called when an item in the navigation drawer is selected.
         */
        void onNavigationDrawerItemSelected(int position);
    }
}

编辑 2：

AtividadePrincipal.java

package br.net.beno.supercarrinho;

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.widget.DrawerLayout;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import br.net.beno.supercarrinho.R;
import com.digits.sdk.android.Digits;
import com.twitter.sdk.android.Twitter;
import com.twitter.sdk.android.core.TwitterAuthConfig;
import com.twitter.sdk.android.core.TwitterCore;
import io.fabric.sdk.android.Fabric;

public class AtividadePrincipal extends AppCompatActivity
        implements NavigationDrawerFragment.NavigationDrawerCallbacks {

    // Note: Your consumer key and secret should be obfuscated in your source code before shipping.
    private static final String TWITTER_KEY = "Dwt1PeE72Ht0znFw1WjVD7ym3";
    private static final String TWITTER_SECRET = "NjxKx3fSfVI5DJ1xcuC5Eqy7AMPaJV5K1kzsCPYIdmxXWeNfoI";


    /**
     * 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);
        TwitterAuthConfig authConfig = new TwitterAuthConfig(TWITTER_KEY, TWITTER_SECRET);
        Fabric.with(this, new Digits(), new Twitter(authConfig));
        setContentView(R.layout.activity_atividade_principal);

        // Trocando a actionbar pela toolbar
        Toolbar mToolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);

        // Gaveta de navegacao

        mNavigationDrawerFragment = (NavigationDrawerFragment)
                getSupportFragmentManager().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 = getSupportFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.container, FragmentoListaCompras.newInstance(position + 1))
                .commit();
    }

    public void onSectionAttached(int number) {
        switch (number) {
            case 1:
                mTitle = getString(R.string.title_section1);
                break;
            case 2:
                mTitle = getString(R.string.title_section2);
                break;
            case 3:
                mTitle = getString(R.string.title_section3);
                break;
        }
    }

    public void restoreActionBar() {
        ActionBar actionBar = getSupportActionBar();
//        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.atividade_principal, 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();

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

        return super.onOptionsItemSelected(item);
    }
}

编辑 3：

activity_atividade_principal.xml：

<!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:id="@+id/drawer_layout"
    android:layout_width="match_parent" android:layout_height="match_parent"
    tools:context="br.net.beno.supercarrinho.AtividadePrincipal">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_height="128dp"
        android:layout_width="match_parent"
        android:minHeight="?android:attr/actionBarSize"
        android:background="@color/colorPrimary"
        android:gravity="bottom" />

    <!-- As the main content view, the view below consumes the entire
         space available using match_parent in both dimensions. -->
    <FrameLayout android:id="@+id/container" android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!-- android:layout_gravity="start" tells DrawerLayout to treat
         this as a sliding drawer on the left side for left-to-right
         languages and on the right side for right-to-left languages.
         If you're not building against API 17 or higher, use
         android:layout_gravity="left" instead. -->
    <!-- The drawer is given a fixed width in dp and extends the full height of
         the container. -->
    <fragment android:id="@+id/navigation_drawer"
        android:layout_width="@dimen/navigation_drawer_width" android:layout_height="match_parent"
        android:layout_gravity="start"
        android:name="br.net.beno.supercarrinho.NavigationDrawerFragment"
        tools:layout="@layout/fragment_navigation_drawer" />

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

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Answer 1

感谢这里的一些 cmets 和回复，以及一些额外的研究，我能够启用它。

正如user5195185 指出的那样，似乎DrawerLayout 必须只有两个孩子：内容（它将附加您放置的任何内容的视图）和抽屉（ ListView)。在 Github 上搜索了一下，我得到了this code。

所以我将我的 Toolbar 小部件与默认的 FrameLayout 放在 LinearLayout 中，但我仍然遇到相同的 NullPointer 错误...

然后我检查了它的代码，我发现他们将主要活动作为上下文传递，所以我使用getActivity()而不是getActionBar().getThemedContext()作为上下文，它起作用了！

之后，我找到this reply，让bar停留在ListView上方，我就设置好了。

所以，我不知道这是否会导致将来出现问题，但这似乎是让 Toolbar 和 NavigationDrawer 一起工作的正确方法。

Answer 2

((AppCompatActivity)getActivity()).getSupportActionBar() 操作栏是活动的一部分，而不是片段。观察您访问操作栏的片段类中的每一行。此外，当您为 Activity 扩展 AppCompatActivity 时，您必须使用 getSupportActionBar。

Answer 3

在调用getActionBar() 或getSupportActionbar() 之前，应将Toolbar 设置为ActionBar。

在调用Fragment 的onCreateView 之前，您是否已经在Activity 的onCreate 中将Toolbar 设置为ActionBar？

Toolbar toolbar = (Toolbar) findViewById(R.id.your_toolbar_id);
setSupportActionBar(toolbar);
// setActionBar(toolbar); // if you are not using AppCompatActivity

编辑：

首先调用NavigationDrawerFragment的onCreateView...

那么你可以移动这些行：

// Trocando a actionbar pela toolbar
Toolbar mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);

到片段：

private ActionBar getActionBar() {
    AppCompatActivity activity = (AppCompatActivity) getActivity();

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

    return activity.getSupportActionBar();
}

上面的代码可能还有一些错误，但是按照这个顺序ActionBar不会为空。

Answer 4

据我了解，android.support.v4.widget.DrawerLayout 应该只有两个孩子：主要内容和导航视图。我认为那里的工具栏是错误的。