我是Android上的新手，正在开发一个包含GoogleMap V2和Markers的项目。 它会显示谷歌地图上的一些位置及其详细信息。如果用户点击地图上的任何标记，它会像往常一样显示带有标记详细信息的MarkerInfoWindow。
当我第一次运行项目时，一切都很好并正常工作。当我在我的应用程序中按下菜单按钮（设备菜单按钮）时，android会退出我的应用程序并像往常一样返回主屏幕。
但是，当我恢复我的应用程序（从菜单屏幕点击应用程序图标）并点击地图上的任何标记我的应用程序粉碎。并给我一个错误。
如果我按下后退按钮（设备后退按钮）直到返回主屏幕退出应用程序，当我像往常一样用图标恢复应用程序时，一切正常，没有崩溃或任何错误。
我的申请有什么问题？当用户使用“菜单”按钮退出应用程序时，为什么我的应用程序崩溃，为什么不在用户退出后退按钮时崩溃？
我知道我的英语不好。但是，我尽我所能。 谢谢你的理解。
我的错误;
01-15 13:18:05.678 3090-3090/com.xxx.xxxapp W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xa62e3288)
01-15 13:18:05.678 3090-3090/com.xxx.xxxapp E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
at com.xxx.xxxapp.MarkerInfoWindowAdapter.getInfoContents(MarkerInfoWindowAdapter.java:25)
at com.google.android.gms.maps.GoogleMap$13.g(Unknown Source)
at com.google.android.gms.maps.internal.d$a.onTransact(Unknown Source)
at android.os.Binder.transact(Binder.java:326)
at com.google.android.gms.maps.internal.p.b(SourceFile:112)
at com.google.maps.api.android.lib6.c.h.a(Unknown Source)
at com.google.maps.api.android.lib6.c.h.a(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.c.h.b(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.c.j.c(Unknown Source)
at com.google.maps.api.android.lib6.c.al.c(Unknown Source)
at com.google.maps.api.android.lib6.c.aj.g(Unknown Source)
at com.google.maps.api.android.lib6.c.al.h(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.c.h.a(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.o.aw.a(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.o.bf.a(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.o.be.a(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.o.bu.d(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.o.ak.onSingleTapConfirmed(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.i.g.onSingleTapConfirmed(Unknown Source)
at com.google.maps.api.android.lib6.gmm6.i.i.handleMessage(Unknown Source)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4745)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
有我的MainActivity类;
import android.os.Bundle;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ActionBarActivity implements ActionBar.TabListener {
SectionsPagerAdapter mSectionsPagerAdapter;
ViewPager mViewPager;
FragmentManager manager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
manager = getSupportFragmentManager();
// Set up the action bar.
final ActionBar actionBar = getSupportActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mSectionsPagerAdapter);
// When swiping between different sections, select the corresponding
// tab. We can also use ActionBar.Tab#select() to do this if we have
// a reference to the Tab.
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// For each of the sections in the app, add a tab to the action bar.
for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
// Create a tab with text corresponding to the page title defined by
// the adapter. Also specify this Activity object, which implements
// the TabListener interface, as the callback (listener) for when
// this tab is selected.
actionBar.addTab(
actionBar.newTab()
.setText(mSectionsPagerAdapter.getPageTitle(i))
.setTabListener(this));
}
}
@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_main, 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);
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
// When the given tab is selected, switch to the corresponding page in
// the ViewPager.
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
}
我的自定义标记信息类;
package com.xxx.xxxapp;
public class Markers {
public String mAdi;
public String mAdres;
public String mTelefon;
public String mFace;
public String mWeb;
public boolean mGeceAcik;
public boolean mMember;
public boolean mBarinak;
public Double mLatitude;
public Double mLongtitude;
public Markers(String mAdi, String mAdres, String mTelefon, String mFace, String mWeb, boolean mBarinak, boolean mGeceAcik, boolean mMember, Double mLatitude, Double mLongtitude) {
this.mAdi = mAdi;
this.mAdres = mAdres;
this.mTelefon = mTelefon;
this.mFace = mFace;
this.mWeb = mWeb;
this.mGeceAcik = mGeceAcik;
this.mMember = mMember;
this.mLatitude = mLatitude;
this.mLongtitude = mLongtitude;
this.mBarinak = mBarinak;
}
public boolean ismBarinak() {
return mBarinak;
}
public void setmBarinak(boolean mBarinak) {
this.mBarinak = mBarinak;
}
public String getmAdi() {
return mAdi;
}
public void setmAdi(String mAdi) {
this.mAdi = mAdi;
}
public String getmAdres() {
return mAdres;
}
public void setmAdres(String mAdres) {
this.mAdres = mAdres;
}
public String getmTelefon() {
return mTelefon;
}
public void setmTelefon(String mTelefon) {
this.mTelefon = mTelefon;
}
public String getmFace() {
return mFace;
}
public void setmFace(String mFace) {
this.mFace = mFace;
}
public String getmWeb() {
return mWeb;
}
public void setmWeb(String mWeb) {
this.mWeb = mWeb;
}
public boolean ismGeceAcik() {
return mGeceAcik;
}
public void setmGeceAcik(boolean mGeceAcik) {
this.mGeceAcik = mGeceAcik;
}
public boolean ismMember() {
return mMember;
}
public void setmMember(boolean mMember) {
this.mMember = mMember;
}
public Double getmLatitude() {
return mLatitude;
}
public void setmLatitude(Double mLatitude) {
this.mLatitude = mLatitude;
}
public Double getmLongtitude() {
return mLongtitude;
}
public void setmLongtitude(Double mLongtitude) {
this.mLongtitude = mLongtitude;
}
}
有我的MapFragment类;
package com.xxx.xxxapp;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
public class HaritaFragment extends Fragment implements LocationListener {
private static GoogleMap mGoogleMap;
public static HashMap<Marker, Markers> mMarkersHashMap;
private ArrayList<Markers> mMyMarkersArray = new ArrayList<Markers>();
private Map<Marker, Markers> allMarkersMap = new HashMap<Marker, Markers>();
private LatLng latLng;
private Double lat;
private Double lng;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_harita, container, false);
}
@Override
public void onResume() {
super.onResume();
// Getting Google Play availability status
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(getActivity().getBaseContext());
if (status != ConnectionResult.SUCCESS) { // Google Play Services are not available
int requestCode = 10;
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, getActivity(), requestCode);
dialog.show();
} else { // Google Play Services are available
setsVetMarkers();
setUpMap();
plotMarkers(mMyMarkersArray);
}
}
private void setsVetMarkers(){
// Initialize the HashMap for Markers and MyMarker object
mMarkersHashMap = new HashMap<Marker, Markers>();
//public Markers(String mAdi, String mAdres, String mTelefon, String mFace, String mWeb, boolean mBarinak, boolean mGeceAcik, boolean mMember, Double mLatitude, Double mLongtitude)
mMyMarkersArray.add(new Markers(
"PetVetam",
"Emirhan cad.",
"0532-555-5555",
"https://www.facebook.com",
"http://www.xxxx.com",
false,
true,
true,
Double.parseDouble("41.05484176"),
Double.parseDouble("29.00497913")));
mMyMarkersArray.add(new Markers("marina", "Muallim Naci Cad. N:49 D:3 Ortaköy Mah.", "0212-265-0000","YOK" ,
"YOK", true, false, true, Double.parseDouble("41.048846"), Double.parseDouble("29.027924")));
mMyMarkersArray.add(new Markers("Animate Vetamats", "Duygu Sk No:2 Levent", "0212-000000","https://www.facebook.com/pages/Animate-Veteriner/562263330470083" ,
"http://www.animate.com.tr", false, false, false, Double.parseDouble("41.094460"), Double.parseDouble("28.998754")));
}
private void plotMarkers(ArrayList<Markers> markers)
{
if(markers.size() > 0)
{
for (Markers myMarker : markers)
{
// Create user marker with custom icon and other options
MarkerOptions markerOption = new MarkerOptions().position(new LatLng(myMarker.getmLatitude(), myMarker.getmLongtitude()));
if (myMarker.ismGeceAcik()){
markerOption.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
}
else if (myMarker.ismBarinak()){
markerOption.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_VIOLET));
}
Marker currentMarker = mGoogleMap.addMarker(markerOption);
mMarkersHashMap.put(currentMarker, myMarker);
allMarkersMap.put(currentMarker, myMarker);
mGoogleMap.setInfoWindowAdapter(new MarkerInfoWindowAdapter());
}
}
}
private void setUpMap(){
mGoogleMap = ((SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map)).getMap();
mGoogleMap.setMyLocationEnabled(true);
// Get the location manager
LocationManager locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use
// default
//Criteria criteria = new Criteria();
//String provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
// Initialize the location fields
//Location eğer varsa mapi usercurrent location ile yaratıyor.
if (location != null) {
onLocationChanged(location);
latLng = new LatLng(lat, lng);
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 15));
//Location yoksa default value ve zoom value ile yaratıyor.
}else{
latLng = new LatLng(41.048846, 29.027924);
Toast.makeText(getActivity(),getActivity().getString(R.string.location_error_message),Toast.LENGTH_LONG).show();
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 10));
}
//OnClick Info Window Listener...
mGoogleMap.setOnInfoWindowClickListener(new GoogleMap.OnInfoWindowClickListener() {
@Override
public void onInfoWindowClick(Marker marker) {
//Set your InfoWindow Click Events...
Markers selectedMarkerInfo = allMarkersMap.get(marker);
Intent intent = new Intent(getActivity(),DetailActivity.class);
intent.putExtra("adi",selectedMarkerInfo.getmAdi());
intent.putExtra("adres",selectedMarkerInfo.getmAdres());
intent.putExtra("web",selectedMarkerInfo.getmWeb());
intent.putExtra("face",selectedMarkerInfo.getmFace());
intent.putExtra("tel",selectedMarkerInfo.getmTelefon());
intent.putExtra("lat",selectedMarkerInfo.getmLatitude().toString());
intent.putExtra("lng",selectedMarkerInfo.getmLongtitude().toString());
intent.putExtra("gece",selectedMarkerInfo.ismGeceAcik());
intent.putExtra("member",selectedMarkerInfo.ismMember());
intent.putExtra("barinak",selectedMarkerInfo.ismBarinak());
startActivity(intent);
}
});
}
@Override
public void onLocationChanged(Location location) {
lat = (Double) (location.getLatitude());
lng = (Double) (location.getLongitude());
}
}
还有MarkerInfoWindowAdapter类;
package com.xxx.xxxapp;
import android.view.View;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.model.Marker;
public class MarkerInfoWindowAdapter implements GoogleMap.InfoWindowAdapter
{
public MarkerInfoWindowAdapter()
{
}
@Override
public View getInfoWindow(Marker marker)
{
return null;
}
@Override
public View getInfoContents(Marker marker)
{
Markers myMarker = HaritaFragment.mMarkersHashMap.get(marker);
marker.setTitle(myMarker.getmAdi());
marker.setSnippet(myMarker.getmAdres());
return null;
}
}
有AndroidManifest.xml;
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.xxx.xxxapp" >
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!--
The following two permissions are not required to use
Google Maps Android API v2, but are recommended.
-->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<meta-data
android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="@string/API_KEY" />
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:screenOrientation="portrait" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".DetailActivity"
android:label="@string/title_activity_detail"
android:screenOrientation="portrait" >
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.xxx.xxxapp.MainActivity" />
</activity>
<activity
android:name=".ListVets"
android:label="@string/title_activity_list_vets"
android:parentActivityName=".MainActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.xxx.xxxapp.MainActivity" />
</activity>
</application>
</manifest>
答案 0 :(得分：2)
确定。我解决了这个问题。
我试图在setsVetMarkers（）方法中初始化HashMap for Markers和MyMarker对象，当我初始化HashMap时，问题就解决了。
就像在 setsVetMarkers 方法中那样;
// Initialize the HashMap for Markers and MyMarker object
mMarkersHashMap = new HashMap<Marker, Markers>();
我在顶部重新创建并初始化;
public static HashMap<Marker, Markers> mMarkersHashMap = new HashMap<Marker, Markers>();
问题解决了。我不想删除这个问题，也许对某人有帮助。但这是一个非常具体的问题。如果某个管理员想删除这个问题，对我来说没问题。