【发布时间】：2019-01-22 14:38:25
【问题描述】：
我已经构建了一个系统，该系统基于在用户四处移动时动态跟踪用户当前位置。该系统运行良好，并一次又一次地将用户的当前位置更新到 firebase 数据库中。但是，当应用程序被最小化并再次恢复到相同的活动（当然是地图）时，它只显示用户的位置，但不会在 fire-base 数据库中更新它。现在我知道活动再次从 OnResume() 方法开始，我尝试了几件事，但每次我尝试做某事时，它大多数时候都说 googleapiClient 未连接，然后立即崩溃。在不操作 onResume 的情况下，应用程序可以完美运行，但是当应用程序被最小化并从 onResume 方法重新打开时，它不会将用户位置更新到火基中。我应该对它开始将用户动态位置发送到火力基地的 onResume() 方法做什么？？？ 下面我发布了我的代码。任何帮助将不胜感激谢谢。
public class RequestLocationMap extends FragmentActivity implements OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks
, GoogleApiClient.OnConnectionFailedListener
, LocationListener {
private static final String TAG = "RequestLocationMap";
private GoogleMap mMap;
private GoogleApiClient googleApiClient;
private LocationRequest locationRequest;
private Location lastLocation;
private Marker currentUserLocationMarker;
public static final int Request_User_Location_Code = 99;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_request_location_map);
Log.d(TAG, "onCreate: called");
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
checkUserLocationPermission();
}
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
@Override
public void onMapReady(GoogleMap googleMap) {
Log.d(TAG, "onMapReady: called");
mMap = googleMap;
if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
buildGoogleApiClient();
mMap.setMyLocationEnabled(true);
}
}
public boolean checkUserLocationPermission() {
Log.d(TAG, "checkUserLocationPermission: called");
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION)) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, Request_User_Location_Code);
} else {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, Request_User_Location_Code);
}
return false;
} else {
return true;
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
Log.d(TAG, "onRequestPermissionsResult: here");
switch (requestCode) {
case Request_User_Location_Code:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
if (googleApiClient == null) {
buildGoogleApiClient();
}
mMap.setMyLocationEnabled(true);
}
} else {
Toast.makeText(this, "Application requires location permission", Toast.LENGTH_SHORT).show();
}
}
}
protected synchronized void buildGoogleApiClient() {
Log.d(TAG, "buildGoogleApiClient: called");
googleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
googleApiClient.connect();
}
@Override
public void onConnected(@Nullable Bundle bundle) {
Log.d(TAG, "onConnected: called");
locationRequest = new LocationRequest();
locationRequest.setInterval(1000);
locationRequest.setFastestInterval(1000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
.addLocationRequest(locationRequest);
builder.setAlwaysShow(true);
PendingResult<LocationSettingsResult> result =
LocationServices.SettingsApi.checkLocationSettings(googleApiClient, builder.build());
result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
@Override
public void onResult(LocationSettingsResult result) {
final Status status = result.getStatus();
final LocationSettingsStates state = result.getLocationSettingsStates();
switch (status.getStatusCode()) {
case LocationSettingsStatusCodes.SUCCESS:
break;
case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
try {
status.startResolutionForResult(
RequestLocationMap.this, 1000);
} catch (IntentSender.SendIntentException e) {
}
break;
case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
break;
}
}
});
if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, locationRequest, this);
}
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
@Override
public void onLocationChanged(Location location) {
Log.d(TAG, "onLocationChanged: called");
lastLocation = location;
if (currentUserLocationMarker != null) {
currentUserLocationMarker.remove();
}
LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(latLng);
markerOptions.title("Current Location");
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
currentUserLocationMarker = mMap.addMarker(markerOptions);
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
mMap.animateCamera(CameraUpdateFactory.zoomTo(14f));
DatabaseReference myTracking = FirebaseDatabase.getInstance().getReference().child("MyTracking");
GeoFire geoFire = new GeoFire(myTracking);
geoFire.setLocation(FirebaseAuth.getInstance().getCurrentUser().getUid(), new GeoLocation(location
.getLatitude(), location.getLongitude()));
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
Log.d(TAG, "onActivityResult: called");
switch (requestCode) {
case 1000:
switch (resultCode) {
case Activity.RESULT_OK: {
break;
}
case Activity.RESULT_CANCELED: {
// The user was asked to change settings, but chose not to
Toast.makeText(RequestLocationMap.this, "App required location permission", Toast.LENGTH_LONG).show();
finish();
break;
}
default: {
break;
}
}
break;
}
}
@Override
protected void onStop() {
Log.d(TAG, "onStop: called");
super.onStop();
LocationServices.FusedLocationApi.removeLocationUpdates(googleApiClient, this);
DatabaseReference myTracking = FirebaseDatabase.getInstance().getReference().child("MyTracking");
GeoFire geoFire = new GeoFire(myTracking);
geoFire.removeLocation(FirebaseAuth.getInstance().getCurrentUser().getUid());
}
@Override
protected void onResume() {
Log.d(TAG, "onResume: called");
super.onResume();
}
}
【问题讨论】：
-
当您的活动停止时，您请求停止从 FusedLocationAPI 接收位置更新。在 onResume(...) 中，您永远不会请求再次开始接收位置更新
-
@WadeWilson 我试过了，它仍然抛出一个错误，说 googleApIClient 尚未连接
-
您只需要在您的 googleAPIClient 实例上调用 connect 即可。我建议从 onResume() 调用“buildGoogleApiClient()”，这样您就可以在活动恢复时随时请求位置更新。然后检查您的 GoogleMap 引用是否在“onLocationChanged”内不为空。如果 MapFragment 的设置时间比 FusedLocationAPI 长，则可能会发生这种情况。
-
@WadeWilson 绝对有效。我只需将 buildGoogleApiClient() 从 onMapReady 移动到 Onresume 并开始检测用户位置。谢谢你
-
没问题。我会把答案写出来供其他人使用。
标签： java android firebase google-maps gps