更改地图视图类型时出现 Googlemap 错误

Question

我在使用 GoogleMap 时遇到了一个新问题。安装 NavigationDrawer 后，我为 GoogleMap 创建了一个新 Fragment，从 Drawer 菜单调用。

我确实实现了 KeyDown 过程，使用音量按钮将地图视图类型从混合切换到普通，反之亦然。

所以当我点击这些后者进行切换时，应用程序崩溃了，即使在我的智能手机上也是如此。

请问您对这类问题有什么想法吗？

最好的问候。

日志猫：

    04-24 10:52:47.101: I/dalvikvm(627): threadid=3: reacting to signal 3
04-24 10:52:47.161: I/dalvikvm(627): Wrote stack traces to '/data/anr/traces.txt'
04-24 10:52:47.311: D/libEGL(627): loaded /system/lib/egl/libGLES_android.so
04-24 10:52:47.321: I/dalvikvm(627): threadid=3: reacting to signal 3
04-24 10:52:47.391: D/libEGL(627): loaded /system/lib/egl/libEGL_emulation.so
04-24 10:52:47.401: D/(627): HostConnection::get() New Host Connection established 0x13a9f8, tid 627
04-24 10:52:47.401: I/dalvikvm(627): Wrote stack traces to '/data/anr/traces.txt'
04-24 10:52:47.413: D/libEGL(627): loaded /system/lib/egl/libGLESv1_CM_emulation.so
04-24 10:52:47.413: D/libEGL(627): loaded /system/lib/egl/libGLESv2_emulation.so
04-24 10:52:47.642: W/EGL_emulation(627): eglSurfaceAttrib not implemented
04-24 10:52:47.661: D/OpenGLRenderer(627): Enabling debug mode 0
04-24 10:52:47.946: I/dalvikvm(627): threadid=3: reacting to signal 3
04-24 10:52:47.951: I/dalvikvm(627): Wrote stack traces to '/data/anr/traces.txt'
04-24 10:52:48.281: I/dalvikvm(627): threadid=3: reacting to signal 3
04-24 10:52:48.321: I/dalvikvm(627): Wrote stack traces to '/data/anr/traces.txt'
04-24 10:53:04.621: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.631: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.631: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.641: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.651: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.661: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.671: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.671: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.681: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.701: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.711: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.721: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.732: W/GooglePlayServicesUtil(627): Google Play services is missing.
04-24 10:53:04.732: W/System.err(627): java.lang.NullPointerException
04-24 10:53:04.741: W/System.err(627):  at app.track.map.MainActivity$GoogleMapFragment.initilizeMap(MainActivity.java:258)
04-24 10:53:04.741: W/System.err(627):  at app.track.map.MainActivity$GoogleMapFragment.onCreateView(MainActivity.java:241)
04-24 10:53:04.741: W/System.err(627):  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:828)
04-24 10:53:04.741: W/System.err(627):  at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1032)
04-24 10:53:04.751: W/System.err(627):  at android.app.BackStackRecord.run(BackStackRecord.java:622)
04-24 10:53:04.751: W/System.err(627):  at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1382)
04-24 10:53:04.751: W/System.err(627):  at android.app.FragmentManagerImpl$1.run(FragmentManager.java:426)
04-24 10:53:04.751: W/System.err(627):  at android.os.Handler.handleCallback(Handler.java:605)
04-24 10:53:04.751: W/System.err(627):  at android.os.Handler.dispatchMessage(Handler.java:92)
04-24 10:53:04.751: W/System.err(627):  at android.os.Looper.loop(Looper.java:137)
04-24 10:53:04.751: W/System.err(627):  at android.app.ActivityThread.main(ActivityThread.java:4424)
04-24 10:53:04.761: W/System.err(627):  at java.lang.reflect.Method.invokeNative(Native Method)
04-24 10:53:04.761: W/System.err(627):  at java.lang.reflect.Method.invoke(Method.java:511)
04-24 10:53:04.761: W/System.err(627):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
04-24 10:53:04.761: W/System.err(627):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
04-24 10:53:04.771: W/System.err(627):  at dalvik.system.NativeStart.main(Native Method)
04-24 10:53:07.231: D/AndroidRuntime(627): Shutting down VM
04-24 10:53:07.231: W/dalvikvm(627): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
04-24 10:53:07.331: E/AndroidRuntime(627): FATAL EXCEPTION: main
04-24 10:53:07.331: E/AndroidRuntime(627): java.lang.NullPointerException
04-24 10:53:07.331: E/AndroidRuntime(627):  at app.track.map.MainActivity.onKeyDown(MainActivity.java:219)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.view.KeyEvent.dispatch(KeyEvent.java:2551)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.app.Activity.dispatchKeyEvent(Activity.java:2329)
04-24 10:53:07.331: E/AndroidRuntime(627):  at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1806)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.view.ViewRootImpl.deliverKeyEventPostIme(ViewRootImpl.java:3327)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.view.ViewRootImpl.handleFinishedEvent(ViewRootImpl.java:3300)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2460)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.os.Handler.dispatchMessage(Handler.java:99)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.os.Looper.loop(Looper.java:137)
04-24 10:53:07.331: E/AndroidRuntime(627):  at android.app.ActivityThread.main(ActivityThread.java:4424)
04-24 10:53:07.331: E/AndroidRuntime(627):  at java.lang.reflect.Method.invokeNative(Native Method)
04-24 10:53:07.331: E/AndroidRuntime(627):  at java.lang.reflect.Method.invoke(Method.java:511)
04-24 10:53:07.331: E/AndroidRuntime(627):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
04-24 10:53:07.331: E/AndroidRuntime(627):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
04-24 10:53:07.331: E/AndroidRuntime(627):  at dalvik.system.NativeStart.main(Native Method)
04-24 10:53:07.561: D/dalvikvm(627): GC_CONCURRENT freed 206K, 4% free 9300K/9607K, paused 4ms+6ms
04-24 10:53:07.982: I/dalvikvm(627): threadid=3: reacting to signal 3
04-24 10:53:08.011: I/dalvikvm(627): Wrote stack traces to '/data/anr/traces.txt'
04-24 10:53:09.441: I/Process(627): Sending signal. PID: 627 SIG: 9

主要活动：

/*
 * Copyright 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package app.track.map;

import java.util.Locale;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.SearchManager;
import android.content.Intent;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.view.KeyEvent;
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.ImageView;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {
    private DrawerLayout mDrawerLayout;
    private ListView mDrawerList;
    private ActionBarDrawerToggle mDrawerToggle;

    private CharSequence mDrawerTitle;
    private CharSequence mTitle;
    private String[] mPlanetTitles;

    // Google Map
    private GoogleMap googleMap;
    private static String SelectedMenuPosition;

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

        mTitle = mDrawerTitle = getTitle();
        mPlanetTitles = getResources().getStringArray(R.array.drawer_array);
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        mDrawerList = (ListView) findViewById(R.id.left_drawer);

        // 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
        mDrawerList.setAdapter(new ArrayAdapter<String>(this,
                R.layout.drawer_list_item, mPlanetTitles));
        mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

        // enable ActionBar app icon to behave as action to toggle nav drawer
        getActionBar().setDisplayHomeAsUpEnabled(true);
        getActionBar().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 */
                R.drawable.ic_drawer,  /* nav drawer image to replace 'Up' caret */
                R.string.drawer_open,  /* "open drawer" description for accessibility */
                R.string.drawer_close  /* "close drawer" description for accessibility */
                ) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
            }

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

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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.map, menu);
        return super.onCreateOptionsMenu(menu);
    }

    /* Called whenever we call invalidateOptionsMenu() */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        // If the nav drawer is open, hide action items related to the content view
        boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
        menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
        return super.onPrepareOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
         // The action bar home/up action should open or close the drawer.
         // ActionBarDrawerToggle will take care of this.
        if (mDrawerToggle.onOptionsItemSelected(item)) {
            return true;
        }
        // Handle action buttons
        switch(item.getItemId()) {
        case R.id.action_websearch:
            // create intent to perform web search for this planet
            Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
            intent.putExtra(SearchManager.QUERY, getActionBar().getTitle());
            // catch event that there's no activity to handle intent
            if (intent.resolveActivity(getPackageManager()) != null) {
                startActivity(intent);
            } else {
                Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
            }
            return true;
        default:
            return super.onOptionsItemSelected(item);
        }
    }

    /* The click listner for ListView in the navigation drawer */
    private class DrawerItemClickListener implements ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            selectItem(position);
        }
    }

    private void selectItem(int position) {
        SelectedMenuPosition = getResources().getStringArray(R.array.drawer_array)[position];
        // update the main content by replacing fragments
        if ( position == 2){
            Fragment fragment = new GoogleMapFragment();

            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();

            // update selected item and title, then close the drawer
            mDrawerList.setItemChecked(position, true);
            setTitle(mPlanetTitles[position]);
            mDrawerLayout.closeDrawer(mDrawerList);
        }
        else if( position == 3){
            // update selected item and title, then close the drawer
            mDrawerList.setItemChecked(position, true);
            setTitle(mPlanetTitles[position]);
            mDrawerLayout.closeDrawer(mDrawerList);
        }
        else
            // update selected item and title, then close the drawer
            mDrawerList.setItemChecked(position, true);
            setTitle(mPlanetTitles[position]);
            mDrawerLayout.closeDrawer(mDrawerList);
    }

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

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(SelectedMenuPosition.equals("Navigate")){
            if (keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
                googleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
                return true;
            } 
            else if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
                googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
                return true;
            }
        }
        return super.onKeyDown(keyCode, event);
    }

GoogleMapFragment

    public static class GoogleMapFragment extends Fragment {
        // Google Map
        private GoogleMap googleMap;

        public GoogleMapFragment() {
            // Empty constructor required for fragment subclasses
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_map, container, false);

            try {
                // Loading map
                initilizeMap();

            } catch (Exception e) {
                e.printStackTrace();
            }

            getActivity().setTitle(SelectedMenuPosition);

            return rootView;
        }

        /**
         * function to load map. If map is not created it will create it for you
         * */
        private void initilizeMap() {
            if (googleMap == null) {
                googleMap = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
                googleMap.getUiSettings().setCompassEnabled(true);
                googleMap.getUiSettings().setRotateGesturesEnabled(true);
                googleMap.getUiSettings().setMyLocationButtonEnabled(true);
                googleMap.setMyLocationEnabled(true);

                LatLng sydney = new LatLng(-33.867, 151.206);

                googleMap.setMyLocationEnabled(true);
                googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(sydney, 13));

                googleMap.addMarker(new MarkerOptions()
                        .title("Sydney")
                        .snippet("The most populous city in Australia.")
                        .position(sydney));

                // check if map is created successfully or not
                if (googleMap == null) {
                    //Toast.makeText(getApplicationContext(),"Sorry! unable to create maps", Toast.LENGTH_SHORT).show();
                }
            }
        }

    }
}

Answer 1

您在尝试设置GoogleMap 类型的onKeyDown 方法中遇到NullPointer 错误。而您忘记在您的onCreate() 方法中初始化您的GoogleMap，这就是应用程序崩溃的原因。

只需在您的班级中初始化您的GoogleMap googleMap。

Answer 2

在清单中添加这个

      <meta-data
android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />