javascript - 构建我的应用程序并安装 Google Maps API 后,每当我倾向于搜索位置时,我的应用程序就会崩溃
问题描述
我是这个编程的新手,我发现很难通过这个阶段。成功构建APP后,我添加了谷歌地图以获取实时位置。执行此操作后,每次单击切换按钮时,我的应用程序都会崩溃。
如果你能帮我找出问题的根源,我会很高兴,因为这对我有很大帮助。下面是我的Logcat
09-22 15:59:04.636 4803-4803/com.example.mac.uberclone E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.mac.uberclone, PID: 4803
java.lang.NullPointerException: Attempt to read from field 'int com.google.android.gms.location.LocationRequest.a' on a null object reference
at android.os.Parcel.createException(Parcel.java:1948)
at android.os.Parcel.readException(Parcel.java:1910)
at android.os.Parcel.readException(Parcel.java:1860)
at com.google.android.gms.internal.location.zza.transactAndReadExceptionReturnVoid(Unknown Source:10)
at com.google.android.gms.internal.location.zzap.zza(Unknown Source:9)
at com.google.android.gms.internal.location.zzas.zza(Unknown Source:44)
at com.google.android.gms.internal.location.zzaz.zza(Unknown Source:5)
at com.google.android.gms.internal.location.zzr.doExecute(Unknown Source:25)
at com.google.android.gms.common.api.internal.BaseImplementation$ApiMethodImpl.run(Unknown Source:10)
at com.google.android.gms.common.api.internal.zzag.execute(Unknown Source:71)
at com.google.android.gms.common.api.internal.zzbd.execute(Unknown Source:5)
at com.google.android.gms.common.api.internal.zzav.execute(Unknown Source:137)
at com.google.android.gms.internal.location.zzq.requestLocationUpdates(Unknown Source:14)
at com.example.mac.uberclone.Welcome.startLocationUpdate(Welcome.java:269)
at com.example.mac.uberclone.Welcome.onConnected(Welcome.java:283)
at com.google.android.gms.common.internal.GmsClientEventManager.onConnectionSuccess(Unknown Source:109)
at com.google.android.gms.common.api.internal.zzav.zzb(Unknown Source:22)
at com.google.android.gms.common.api.internal.zzaj.zzat(Unknown Source:92)
at com.google.android.gms.common.api.internal.zzaj.onConnected(Unknown Source:21)
at com.google.android.gms.common.api.internal.zzbd.onConnected(Unknown Source:7)
at com.google.android.gms.common.api.internal.zzp.onConnected(Unknown Source:5)
at com.google.android.gms.common.internal.zzf.onConnected(Unknown Source:2)
at com.google.android.gms.common.internal.BaseGmsClient$PostInitCallback.handleServiceSuccess(Unknown Source:130)
at com.google.android.gms.common.internal.BaseGmsClient$zza.deliverCallback(Unknown Source:62)
at com.google.android.gms.common.internal.BaseGmsClient$zza.deliverCallback(Unknown Source:2)
at com.google.android.gms.common.internal.BaseGmsClient$CallbackProxy.deliverCallback(Unknown Source:51)
at com.google.android.gms.common.internal.BaseGmsClient$zzb.handleMessage(Unknown Source:270)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
同样在我的 Build Gradle 应用程序中
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.github.glomadrian:MaterialAnimatedSwitch:1.1@aar'
implementation 'com.firebase:geofire-android:2.3.1'
implementation 'com.android.support:appcompat-v7:28.0.0-rc02'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.google.firebase:firebase-auth:16.0.3'
implementation 'com.google.android.gms:play-services-maps:15.0.1'
implementation 'com.google.android.gms:play-services-location:15.0.1'
implementation 'com.google.android.gms:play-services-analytics:16.0.3'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
//Add Library
implementation 'com.github.d-max:spots-dialog:0.7@aar'
implementation 'uk.co.chrisjenx:calligraphy:latest.integration'
implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.rengwuxian.materialedittext:library:2.1.4'
implementation 'com.android.support:design:28.0.0'
implementation 'com.android.support:cardview-v7:28.0.0'
implementation 'com.google.firebase:firebase-core:16.0.3'
implementation 'com.google.firebase:firebase-database:16.0.2'
implementation 'com.firebaseui:firebase-ui-database:4.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
}
apply plugin: 'com.google.gms.google-services'
这是我的欢迎活动
package com.example.mac.uberclone;
import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Handler;
import android.os.SystemClock;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import android.widget.Toast;
import com.firebase.geofire.GeoFire;
import com.firebase.geofire.GeoLocation;
import com.github.glomadrian.materialanimatedswitch.MaterialAnimatedSwitch;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
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 com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class Welcome extends FragmentActivity implements
OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
LocationListener
{
private GoogleMap mMap;
//Play Service
private static final int MY_PERMISSION_REQUEST_CODE = 7000;
private static final int PLAY_SERVICE_RES_REQUEST = 7001;
private LocationRequest locationRequest;
private GoogleApiClient mGoogleApiClient;
private Location mLastLocation;
private static int UPDATE_INTERVAL = 5000;
private static int FASTEST_INTERVAL = 3000;
private static int DISPLACEMENT = 10;
DatabaseReference drivers;
GeoFire geoFire;
Marker mCurrent;
MaterialAnimatedSwitch location_switch;
SupportMapFragment mapFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_welcome);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
//Init View
location_switch = (MaterialAnimatedSwitch)findViewById(R.id.location_switch);
location_switch.setOnCheckedChangeListener(new MaterialAnimatedSwitch.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(boolean isOnline) {
if (isOnline)
{
startLocationUpdate();
displayLocation();
Snackbar.make(mapFragment.getView(),"You are online",Snackbar.LENGTH_SHORT)
.show();
}
else
{
stopLocationUpdate();
mCurrent.remove();
Snackbar.make(mapFragment.getView(),"You are offline",Snackbar.LENGTH_SHORT)
.show();
}
}
});
//Geo Fire
drivers = FirebaseDatabase.getInstance().getReference("Drivers");
geoFire = new GeoFire (drivers);
setUpLocation();
}
//Press Ctrl+O
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode)
{
case MY_PERMISSION_REQUEST_CODE:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
{
if (checkPlayServices())
{
buildGoogleApiClient();
createLocationRequest();
if (location_switch.isChecked())
displayLocation();
}
}
}
}
private void setUpLocation() {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)
{
//Request runtime permission
ActivityCompat.requestPermissions(this, new String[]{
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION
},MY_PERMISSION_REQUEST_CODE);
}
else
{
if (checkPlayServices())
{
buildGoogleApiClient();
createLocationRequest();
if (location_switch.isChecked())
displayLocation();
}
}
}
private void createLocationRequest() {
LocationRequest locationRequest = LocationRequest.create();
locationRequest.setInterval(5000);
locationRequest.setFastestInterval(1000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
private void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
mGoogleApiClient.connect();
}
private boolean checkPlayServices() {
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (resultCode != ConnectionResult.SUCCESS)
{
if (GooglePlayServicesUtil.isUserRecoverableError(resultCode))
GooglePlayServicesUtil.getErrorDialog(resultCode,this,PLAY_SERVICE_RES_REQUEST).show();
else {
Toast.makeText(this, "This device is not supported", Toast.LENGTH_SHORT).show();
finish();
}
return false;
}
return true;
}
private void stopLocationUpdate() {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)
{
return;
}
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient,this);
}
private void displayLocation() {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)
{
return;
}
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (mLastLocation != null)
{
if (location_switch.isChecked())
{
final double latitude = mLastLocation.getLatitude();
final double longitude = mLastLocation.getLongitude();
//Update to firebase
geoFire.setLocation(FirebaseAuth.getInstance().getCurrentUser().getUid(), new GeoLocation(latitude, longitude), new GeoFire.CompletionListener() {
@Override
public void onComplete(String key, DatabaseError error) {
//Add marker
if (mCurrent != null)
mCurrent.remove(); //Remove already marker
mCurrent = mMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromResource(R.drawable.car))
.position(new LatLng(latitude,longitude))
.title("You"));
// Move camera to this position
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(latitude,longitude),15.0f));
//Draw animation rotate marker
rotateMarker(mCurrent,-360,mMap);
}
});
}
else
{
Log.d("Error", "Cannot get your location");
}
}
}
private void rotateMarker(final Marker mCurrent, final float i, GoogleMap mMap) {
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
final float startRotation = mCurrent.getRotation();
final long duration = 1500;
final Interpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
@Override
public void run() {
long elapsed = SystemClock.uptimeMillis() - start;
float t = interpolator.getInterpolation((float)elapsed/duration);
float rot = t*i+(1-t)*startRotation;
mCurrent.setRotation(-rot > 180?rot/2:rot);
if (t<1.0)
{
handler.postDelayed(this,16);
}
}
});
}
private void startLocationUpdate() {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)
{
return;
}
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,locationRequest,this);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
}
@Override
public void onConnected(@Nullable Bundle bundle) {
displayLocation();
startLocationUpdate();
}
@Override
public void onConnectionSuspended(int i) {
mGoogleApiClient.connect();
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
@Override
public void onLocationChanged(Location location) {
mLastLocation = location;
displayLocation();
}
}
解决方案
private void createLocationRequest() {
LocationRequest locationRequest = LocationRequest.create();
locationRequest.setInterval(5000);
locationRequest.setFastestInterval(1000);
locationRequest.setPriority (LocationRequest.PRIORITY_HIGH_ACCURACY);
this.locationRequest = locationRequest;
}
这就是问题的解决方案。
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