com.google.android.gms.maps.GoogleMap.addMarker(com.google.android.gms.maps.model.MarkerOptions)和#x27;关于空对象引用
我正试图在com.google.android.gms.maps.GoogleMap.addMarker(com.google.android.gms.maps.model.MarkerOptions)和#x27;关于空对象引用,android,google-maps,Android,Google Maps,我正试图在Map活动启动时借助GoogleAppClient到达最后一个已知位置。我遵循了链接中的指南: 它可以工作,但应用程序有时会崩溃,我得到以下错误: 我怎样才能修好它 错误: 08-28 16:10:11.687: E/AndroidRuntime(5937): FATAL EXCEPTION: main 08-28 16:10:11.687: E/AndroidRuntime(5937): Process: com.bustracker, PID: 5937 08-28 16:10:
Map
活动启动时借助GoogleAppClient
到达最后一个已知位置。我遵循了链接中的指南:
它可以工作,但应用程序有时会崩溃,我得到以下错误:
我怎样才能修好它
错误:
08-28 16:10:11.687: E/AndroidRuntime(5937): FATAL EXCEPTION: main
08-28 16:10:11.687: E/AndroidRuntime(5937): Process: com.bustracker, PID: 5937
08-28 16:10:11.687: E/AndroidRuntime(5937): java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.android.gms.maps.model.Marker com.google.android.gms.maps.GoogleMap.addMarker(com.google.android.gms.maps.model.MarkerOptions)' on a null object reference
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.bustracker.Map.onConnected(Map.java:494)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzj.zzg(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.api.zze.zzmH(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.api.zze.onConnected(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.api.zzg$2.onConnected(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zzg.zznO(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zza.zzc(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zza.zzr(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zzc.zznQ(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zzb.handleMessage(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at android.os.Handler.dispatchMessage(Handler.java:102)
08-28 16:10:11.687: E/AndroidRuntime(5937): at android.os.Looper.loop(Looper.java:145)
08-28 16:10:11.687: E/AndroidRuntime(5937): at android.app.ActivityThread.main(ActivityThread.java:5944)
08-28 16:10:11.687: E/AndroidRuntime(5937): at java.lang.reflect.Method.invoke(Native Method)
08-28 16:10:11.687: E/AndroidRuntime(5937): at java.lang.reflect.Method.invoke(Method.java:372)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1389)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1184)
public class Map extends FragmentActivity implements OnMapReadyCallback, ConnectionCallbacks, OnConnectionFailedListener{
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
buildGoogleApiClient();
mGoogleApiClient.connect();
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
System.out.println("ABC buildGoogleApiClient map was invoked: ");
}
@Override
public void onConnected(Bundle arg0) {
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
mGoogleApiClient);
if (mLastLocation != null) {
double lng = mLastLocation.getLongitude();
double lat = mLastLocation.getLatitude();
if(myLocatMarker != null){
myLocatMarker.remove();
}
LatLng ll = new LatLng(lat, lng);
MarkerOptions markerOpt = new MarkerOptions().title("my location")
.position(ll)
.icon(BitmapDescriptorFactory.fromResource(R.drawable.myloc));
System.out.println("ABC onConnected map: "+ lat + " ; " + lng);
myLocatMarker = map.addMarker(markerOpt);
}
}
}
地图活动:
08-28 16:10:11.687: E/AndroidRuntime(5937): FATAL EXCEPTION: main
08-28 16:10:11.687: E/AndroidRuntime(5937): Process: com.bustracker, PID: 5937
08-28 16:10:11.687: E/AndroidRuntime(5937): java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.android.gms.maps.model.Marker com.google.android.gms.maps.GoogleMap.addMarker(com.google.android.gms.maps.model.MarkerOptions)' on a null object reference
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.bustracker.Map.onConnected(Map.java:494)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzj.zzg(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.api.zze.zzmH(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.api.zze.onConnected(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.api.zzg$2.onConnected(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zzg.zznO(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zza.zzc(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zza.zzr(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zzc.zznQ(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.google.android.gms.common.internal.zzi$zzb.handleMessage(Unknown Source)
08-28 16:10:11.687: E/AndroidRuntime(5937): at android.os.Handler.dispatchMessage(Handler.java:102)
08-28 16:10:11.687: E/AndroidRuntime(5937): at android.os.Looper.loop(Looper.java:145)
08-28 16:10:11.687: E/AndroidRuntime(5937): at android.app.ActivityThread.main(ActivityThread.java:5944)
08-28 16:10:11.687: E/AndroidRuntime(5937): at java.lang.reflect.Method.invoke(Native Method)
08-28 16:10:11.687: E/AndroidRuntime(5937): at java.lang.reflect.Method.invoke(Method.java:372)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1389)
08-28 16:10:11.687: E/AndroidRuntime(5937): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1184)
public class Map extends FragmentActivity implements OnMapReadyCallback, ConnectionCallbacks, OnConnectionFailedListener{
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
buildGoogleApiClient();
mGoogleApiClient.connect();
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
System.out.println("ABC buildGoogleApiClient map was invoked: ");
}
@Override
public void onConnected(Bundle arg0) {
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
mGoogleApiClient);
if (mLastLocation != null) {
double lng = mLastLocation.getLongitude();
double lat = mLastLocation.getLatitude();
if(myLocatMarker != null){
myLocatMarker.remove();
}
LatLng ll = new LatLng(lat, lng);
MarkerOptions markerOpt = new MarkerOptions().title("my location")
.position(ll)
.icon(BitmapDescriptorFactory.fromResource(R.drawable.myloc));
System.out.println("ABC onConnected map: "+ lat + " ; " + lng);
myLocatMarker = map.addMarker(markerOpt);
}
}
}
这是因为没有定义和初始化贴图对象。在全球范围内宣布:
GoogleMap
我想您在onMapReady
尝试在onMapReady
回调中调用mGoogleApiClient.connect()
,以确保映射不为空
如果您不想正确使用异步,只需使用同步方式获取映射即可
删除这个mapFragment.getMapAsync(这个)代码>
并添加这个map=mapFragment.getMap()代码>
确保您有字段GoogleMap
,因为您将其隐藏在代码中
或者这是另一个版本
public class Map extends FragmentActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {
GoogleMap map;
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
Marker myLocatMarker;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
buildGoogleApiClient();
mapFragment.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(GoogleMap googleMap) {
map = googleMap;
mGoogleApiClient.connect();
}
});
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
System.out.println("ABC buildGoogleApiClient map was invoked: ");
}
@Override
public void onConnected(Bundle arg0) {
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (mLastLocation != null) {
double lng = mLastLocation.getLongitude();
double lat = mLastLocation.getLatitude();
if (myLocatMarker != null) {
myLocatMarker.remove();
}
LatLng ll = new LatLng(lat, lng);
MarkerOptions markerOpt = new MarkerOptions().title("my location")
.position(ll)
.icon(BitmapDescriptorFactory.fromResource(R.drawable.myloc));
System.out.println("ABC onConnected map: " + lat + " ; " + lng);
myLocatMarker = map.addMarker(markerOpt);
}
}
}
我已经在initMap()中对其进行了初始化。我没有添加wohle活动代码,因为它将持续。我尝试了您的建议,但没有调用回调onMapReady()
。我正在onCreate()
中调用getmapsync
!getMapAsync(new OnMapReadyCallback(){public void onMapReady(GoogleMap-GoogleMap){}});你应该在mapready上获取map,否则它将始终为null。我无法在注释中使用代码来跟踪你。我该把它放在哪里?