我正在按照教程创建一个简单的航空地图。
错误详情：
12-04 11:55:51.216 22405-22405/usc.forecast.weather E/AndroidRuntime: FATAL EXCEPTION: main
Process: usc.forecast.weather, PID: 22405
java.lang.RuntimeException: Unable to start activity ComponentInfo{usc.forecast.weather/usc.forecast.weather.MapActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
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:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.hamweather.aeris.maps.AerisMapView.init(AerisMapView.java:219)
at usc.forecast.weather.MapFragment.onCreateView(MapFragment.java:32)**
at android.app.Fragment.performCreateView(Fragment.java:1700)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:890)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
at android.app.BackStackRecord.run(BackStackRecord.java:684)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1447)
at android.app.Activity.performStart(Activity.java:5240)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2157)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
mapView.init（savedInstanceState，AerisMapType.GOOGLE）;
在AerisMapView.java（第三方，aeris weather）
的init方法中public void init(Bundle savedInstanceState, AerisMapView.AerisMapType type) {
this.type = type;
switch(null.$SwitchMap$com$hamweather$aeris$maps$AerisMapView$AerisMapType[type.ordinal()]) {
case 1:
this.mapView.onCreate(savedInstanceState);
MapsInitializer.initialize(this.getContext());
this.googleMap = this.mapView.getMap(); <-------
this.googleMap.getUiSettings().setZoomControlsEnabled(false);
this.googleMap.setOnCameraChangeListener(this);
this.googleMap.setOnMarkerClickListener(this);
this.markerAdapter = new AerisGoogleInfoAdapter();
this.googleMap.setOnInfoWindowClickListener(this);
this.googleMap.setInfoWindowAdapter(this.markerAdapter);
default:
}
}
我的代码：
MapFragment.java
public class MapFragment extends MapViewFragment implements OnAerisMapLongClickListener, AerisCallback {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
AerisEngine.initWithKeys(this.getString(R.string.aeris_client_id), this.getString(R.string.aeris_client_secret), "usc.forecast.weather");
View view = inflater.inflate(R.layout.fragment_interactive_maps, container, false);
mapView = (AerisMapView) view.findViewById(R.id.aerisfragment_map);
mapView.init(savedInstanceState, AerisMapType.GOOGLE);
Bundle bundle = getArguments();
String lat = bundle.getString("lat");
String lng = bundle.getString("lng");
Location location = new Location("");
location.setLatitude(Double.valueOf(lat));
location.setLongitude(Double.valueOf(lng));
mapView.moveToLocation(location);
mapView.addLayer(AerisTile.RADSAT);
mapView.setOnAerisMapLongClickListener(this);
return view;
}
@Override
public void onMapLongClick(double lat, double longitude) {
// code to handle map long press. i.e. Fetch current conditions?
// see demo app MapFragment.java
}
@Override
public void onResult(EndpointType type, AerisResponse response) {
}}
MapActivity.java
public class MapActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
Intent intent = getIntent();
String lat = intent.getStringExtra("lat");
String lng = intent.getStringExtra("lng");
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
MapFragment fragment = new MapFragment();
Bundle bundle = new Bundle();
bundle.putString("lat", lat);
bundle.putString("lng", lng);
fragment.setArguments(bundle);
fragmentTransaction.add(R.id.fragment_container, fragment);
fragmentTransaction.commit();
}}
activity_map.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
fragment_interactive_maps.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<com.hamweather.aeris.maps.AerisMapView
android:id="@+id/aerisfragment_map"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1" >
</com.hamweather.aeris.maps.AerisMapView>
</LinearLayout>
的build.gradle（项目）
apply plugin: 'com.android.application'
android {
compileSdkVersion 21
buildToolsVersion "21.1.2"
defaultConfig {
applicationId "usc.forecast.weather"
minSdkVersion 19
targetSdkVersion 21
versionCode 1
versionName "1.0"
multiDexEnabled true
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:21.0.3'
compile 'com.google.android.gms:play-services-maps:8.3.0'
compile 'com.facebook.android:facebook-android-sdk:4.6.0'
compile 'com.hamweather:aeris-maps-library:1.1.1@aar'}
答案 0 :(得分：1)
发生这种情况的原因是我手机上的Google Play服务已过时。最新版本的Android Studio使用最新的API SDK来编译应用程序，因此谷歌地图返回null。
答案 1 :(得分：0)
确保在这些生命周期事件中包含这些MapView次调用。
@Override
public void onResume() {
mapView.onResume();
super.onResume();
}
@Override
public void onPause() {
super.onPause();
mapView.onPause();
}
@Override
public void onDestroy() {
super.onDestroy();
mapView.onDestroy();
}
@Override
public void onLowMemory() {
super.onLowMemory();
mapView.onLowMemory();
}
编辑：要使MapFragment初始化并开始使用它，通常需要这样做：
mapFragment.getMapAsync(this);
然后当它加载时，这个覆盖被调用然后你可以使用它（这可能就是为什么它太空了，因为你试图过早地使用它。）
@Override
public void onMapReady(GoogleMap googleMap) {
}
另外，请确保在Fragment或Activity：
implements OnMapReadyCallback
MapFragment不需要像MapView那样绑定到生命周期中（上图），因为它是Fragment并且自己处理它。
答案 2 :(得分：0)
我看到这个问题链接到（当前）com.google.android.gms：play-services-maps：9.4版本的地图SDK，我相信这个问题也出现在9.2.1中。
Aeris已经认识到了这个问题，并建议您坚持使用com.google.android.gms：play-services：8.4.0直到它们出来并进行SDK更新（计划于2016年第四季度开始）。