问题Android Studio 1.0.2：致命异常：主进程java.lang.NullPointerException

Question

所以，我正在做这个项目，其中包括一个介绍活动，切换到带导航抽屉的菜单活动。几天前，我有一个问题从简介切换到菜单（Android Studio 1.0.2: java.lang.RuntimeException: Unable to start activity ComponentInfo: java.lang.NullPointerException），并且通过将name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar" 更改为 name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar"来解决问题，这要归功于goonerdroid的建议我之前的链接。我现在的问题是我试图在导航抽屉旁边的操作栏的右上角添加搜索操作，以便它可以搜索我将要添加的不同的未来活动和javas。当我运行程序时，它会毫无问题地进入介绍活动。当我单击按钮将我带到menuactivity时，它会显示以下错误：

FATAL EXCEPTION: main
Process: com.wlodsgn.bunbunup, PID: 916
java.lang.NullPointerException
        at com.wlodsgn.bunbunup.MenuActivity.onPrepareOptionsMenu(MenuActivity.java:181)
        at android.app.Activity.onPreparePanel(Activity.java:2556)
        at android.support.v4.app.FragmentActivity.onPrepareOptionsPanel(FragmentActivity.java:469)
        at android.support.v7.app.ActionBarActivity.superOnPrepareOptionsPanel(ActionBarActivity.java:284)
        at android.support.v7.app.ActionBarActivityDelegate.onPrepareOptionsPanel(ActionBarActivityDelegate.java:204)
        at android.support.v7.app.ActionBarActivity.onPrepareOptionsPanel(ActionBarActivity.java:256)
        at android.support.v4.app.FragmentActivity.onPreparePanel(FragmentActivity.java:458)
        at android.support.v7.app.ActionBarActivity.superOnPreparePanel(ActionBarActivity.java:280)
        at android.support.v7.app.ActionBarActivityDelegate$1.onPreparePanel(ActionBarActivityDelegate.java:84)
        at android.support.v7.app.ActionBarActivityDelegateBase.preparePanel(ActionBarActivityDelegateBase.java:1006)
        at android.support.v7.app.ActionBarActivityDelegateBase.doInvalidatePanelMenu(ActionBarActivityDelegateBase.java:1182)
        at android.support.v7.app.ActionBarActivityDelegateBase.access$100(ActionBarActivityDelegateBase.java:79)
        at android.support.v7.app.ActionBarActivityDelegateBase$1.run(ActionBarActivityDelegateBase.java:118)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5017)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
        at dalvik.system.NativeStart.main(Native Method)

这是我更新的MenuActivity.java：

import java.util.ArrayList;

import android.support.v4.view.MenuItemCompat;
import android.support.v4.view.MenuItemCompat.OnActionExpandListener;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.SearchView;
import android.support.v7.widget.SearchView.OnQueryTextListener;
import android.widget.TextView;
import android.widget.Toast;


import android.app.Fragment;
import android.app.FragmentManager;
import android.content.res.Configuration;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.widget.DrawerLayout;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;

/**
 * Created by WiLo on 2/13/2015.
 */
public class MenuActivity extends ActionBarActivity implements OnQueryTextListener, OnActionExpandListener{

    private TextView texto;

    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;

    // nav drawer title
    private CharSequence mDrawerTitle;

    // used to store app title
    private CharSequence mTitle;

    // slide menu items
    private String[] navMenuTitles;
    private TypedArray navMenuIcons;

    private ArrayList<NavDrawerItem> navDrawerItems;
    private NavDrawerListAdapter adapter;

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

        texto = (TextView) findViewById(R.id.texto);

        mTitle = mDrawerTitle = getTitle();

        // load slide menu items
        navMenuTitles = getResources().getStringArray(R.array.nav_drawer_items);

        // nav drawer icons from resources
        navMenuIcons = getResources()
                .obtainTypedArray(R.array.nav_drawer_icons);

        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.list_slidermenu);

        navDrawerItems = new ArrayList<NavDrawerItem>();

        // agregar un nuevo item al menu deslizante
        // Favoritos
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[0], navMenuIcons.getResourceId(0, -1)));
        // Pedidos
        navDrawerItems.add(new NavDrawerItem(navMenuTitles[1], navMenuIcons.getResourceId(1, -1)));
        // Catologo
        //navDrawerItems.add(new NavDrawerItem(navMenuTitles[2], navMenuIcons.getResourceId(2, -1), true, "Estrenos"));
        // Contacto
        //navDrawerItems.add(new NavDrawerItem(navMenuTitles[3], navMenuIcons.getResourceId(3, -1)));

        // Recycle the typed array
        navMenuIcons.recycle();

        mDrawerList.setOnItemClickListener(new SlideMenuClickListener());

        // setting the nav drawer list adapter
        adapter = new NavDrawerListAdapter(getApplicationContext(),
                navDrawerItems);
        mDrawerList.setAdapter(adapter);

        // enabling action bar app icon and behaving it as toggle button
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setHomeButtonEnabled(true);

        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_drawer, //nav menu toggle icon
                R.string.app_name, // nav drawer open - description for accessibility
                R.string.app_name // nav drawer close - description for accessibility
        ) {
            public void onDrawerClosed(View view) {
                getSupportActionBar().setTitle(mTitle);
                // calling onPrepareOptionsMenu() to show action bar icons
                invalidateOptionsMenu();
            }

            public void onDrawerOpened(View drawerView) {
                getSupportActionBar().setTitle(mDrawerTitle);
                // calling onPrepareOptionsMenu() to hide action bar icons
                invalidateOptionsMenu();
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);

        if (savedInstanceState == null) {
            // on first time display view for first nav item
            displayView(0);
        }
    }

    @Override
    public boolean onMenuItemActionExpand(MenuItem menuItem) {
        Toast.makeText(getApplicationContext(), "Abriendo Busqueda", Toast.LENGTH_SHORT).show();
        return true;
    }

    @Override
    public boolean onMenuItemActionCollapse(MenuItem menuItem) {
        Toast.makeText(getApplicationContext(), "Cerrando Busqueda", Toast.LENGTH_SHORT).show();
        return true;
    }

    @Override
    public boolean onQueryTextSubmit(String s) {
        texto.setText("Buscando...\n\n" + s);
        return false;
    }

    @Override
    public boolean onQueryTextChange(String s) {
        texto.setText("Que buscas? \n\n" + s);
        return false;
    }

    /**
     * Slide menu item click listener
     * */
    private class SlideMenuClickListener implements
            ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                                long id) {
            // display view for selected nav drawer item
            displayView(position);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu, menu);

        MenuItem searchItem = menu.findItem(R.id.menu3_buscar);

        SearchView searchView = (SearchView) MenuItemCompat.getActionView(searchItem);
        searchView.setOnQueryTextListener(this);

        MenuItemCompat.setOnActionExpandListener(searchItem, this);

        return super.onCreateOptionsMenu(menu);
    }

    /* *
     * Called when invalidateOptionsMenu() is triggered
     */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // if nav drawer is opened, hide the action items
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        menu.findItem(R.id.action_settings).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }

    /**
     * Diplaying fragment view for selected nav drawer list item
     * */
    private void displayView(int position) {
        // update the main content by replacing fragments
        Fragment fragment = null;
        switch (position) {
            case 0:
                fragment = new FmMenu();
                break;
            case 1:
                fragment = new FmContacto();
                break;

            default:
                break;
        }

        if (fragment != null) {
            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
                    .replace(R.id.frame_container, fragment).commit();

            // update selected item and title, then close the drawer
            mDrawerList.setItemChecked(position, true);
            mDrawerList.setSelection(position);
            setTitle(navMenuTitles[position]);
            mDrawerLayout.closeDrawer(mDrawerList);
        } else {
            // error in creating fragment
            Log.e("BunBunUp", "MenuActivity - Error cuando se creo el fragment");
        }
    }

    @Override
    public void setTitle(CharSequence title) {
        mTitle = title;
        getSupportActionBar().setTitle(mTitle);
    }

    /**
     * When using the ActionBarDrawerToggle, you must call it during
     * onPostCreate() and onConfigurationChanged()...
     */

    @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);
        // Pass any configuration change to the drawer toggls
        mDrawerToggle.onConfigurationChanged(newConfig);
    }

}

我的styles.xml：

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat">
    <!-- Customize your theme here. -->
</style>


</resources>

更新了IntroActivity.java

import android.app.Activity;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.Window;

/**
 * Created by WiLo on 2/13/2015.
 */
public class IntroActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().requestFeature(Window.FEATURE_ACTION_BAR);
        /*getActionBar().hide();*/
        setContentView(R.layout.activity_intro);
        Log.i("BunBunUp", "MainActivity Created");
    }

    /**@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_intro, 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;
        }

        return super.onOptionsItemSelected(item);
    }**/

    public void startMenuActivity(View v){
        Intent intent = new Intent(IntroActivity.this, MenuActivity.class);
        startActivity(intent);
    }

    protected void onResume(){
        super.onResume();
        Log.i("BunBunUp", "IntroActivity Resumed");
    }

    protected void onPause(){
        super.onPause();
        Log.i("BunBunUp", "IntroActivity Paused");
    }

    protected void onStop(){
        super.onStop();
        Log.i("BunBunUp", "IntroActivity Stopped");
    }
}

如果您需要调试或任何其他信息，请与我们联系。任何帮助将不胜感激。

Answer 1

您正在将MenuActivity扩展为ActionBarActivity，这就是为什么要求您使用Theme.AppCompat。它不是关于您所针对的api级别。请记住ActionBarActivity依赖于Theme.AppCompat。如果不应用Theme.AppCompat，则无法使用它。