我正在尝试显示显示当前位置的google地图。但是，当调用地图活动时，它将打开活动，显示地图，然后关闭应用程序。如何防止这种情况发生？ 下面是地图活动的Java代码。
package com.example.nibebe;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.widget.SwitchCompat;
import androidx.core.app.ActivityCompat;
import androidx.fragment.app.FragmentActivity;
import android.annotation.SuppressLint;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.firebase.geofire.GeoFire;
import com.firebase.geofire.GeoLocation;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.FusedLocationProviderClient;
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.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class DriverMapActivity extends FragmentActivity implements
OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener,
com.google.android.gms.location.LocationListener {
private GoogleMap mMap;
GoogleApiClient mGoogleApiClient;
Location mLastLocation;
LocationRequest mLocationRequest;
SupportMapFragment mapFragment;
FusedLocationProviderClient fusedLocationClient;
Button mLogout;
Button mDriver, mPassenger;
@SuppressLint("WrongViewCast")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_driver_map);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.driver_map);
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(DriverMapActivity.this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_REQUEST_CODE);
}else{
mapFragment.getMapAsync(this);
}
fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
mLogout = findViewById(R.id.logout);
mDriver = findViewById(R.id.driver);
mPassenger = findViewById(R.id.passenger);
mLogout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FirebaseAuth.getInstance().signOut();
Intent intent = new Intent(DriverMapActivity.this,MainActivity.class);
startActivity(intent);
finish();
}
});
mPassenger.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(DriverMapActivity.this,PassengerMapActivity.class);
startActivity(intent);
finish();
}
});
mDriver.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "You are already a driver!", Toast.LENGTH_SHORT).show();
}
});
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
/* Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(-34, 151);
mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));*/
fusedLocationClient.getLastLocation()
.addOnSuccessListener(this, new OnSuccessListener<Location>() {
@Override
public void onSuccess(Location location) {
// Got last known location. In some rare situations this can be null.
if (location != null) {
//pass the two parameter
LatLng sydney = new LatLng(location.getLatitude(), location.getLongitude());
mMap.addMarker(new MarkerOptions().position(sydney)
.title("Marker in My current location"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
}
});
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(DriverMapActivity.this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_REQUEST_CODE);
}
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
protected synchronized void buildGoogleApiClient()
{
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
mGoogleApiClient.connect();
}
@Override
public void onConnected(@Nullable Bundle bundle) {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(1000);
mLocationRequest.setFastestInterval(1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(DriverMapActivity.this, new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_REQUEST_CODE);
}
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
@Override
public void onLocationChanged(Location location) {
if(getApplicationContext()!=null){
mLastLocation = location;
LatLng latLng = new LatLng(location.getLatitude(),location.getLongitude());
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
mMap.animateCamera(CameraUpdateFactory.zoomTo(11));
String userId = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("DriversAvailable");
GeoFire geofire = new GeoFire(ref);
geofire.setLocation(userId, new GeoLocation(location.getLatitude(), location.getLongitude()));
}
}
final int LOCATION_REQUEST_CODE = 1;
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case LOCATION_REQUEST_CODE: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
mapFragment.getMapAsync(this);
} else {
Toast.makeText(getApplicationContext(), "Please provide the permission", Toast.LENGTH_LONG).show();
}
break;
}
}
}
@Override
protected void onStop() {
super.onStop();
String userId = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("DriversAvailable");
GeoFire geofire = new GeoFire(ref);
geofire.removeLocation(userId);
}
}
我希望地图能够加载并显示当前位置，而不会导致应用崩溃。 预先感谢！