获取用户粗略坐标：Google API更新后的最新实现方法求助

Hey there, let's work through this location issue step by step—sounds like a mix of simulator quirks, API changes, and thread handling gotchas. Here's what you can check and fix:

Android 4.0 simulators don't have real GPS hardware, so you need to manually inject location data for testing:

• Open the emulator's Extended Controls (the three-dot icon), go to the Location tab, input a latitude/longitude or pick a preset location, then click Send.
• Alternatively, use this adb command to push a location update:

  adb shell am startservice -a com.google.android.gms.location.FusedLocationService --es request "{\"priority\":100,\"interval\":1000,\"fastestInterval\":500}"
  

If the simulator isn't receiving mock locations, even a perfect code setup won't return coordinates.

You mentioned adapting permissions for Android 6.0, but double-check these details:

• Make sure your AndroidManifest.xml includes the required permissions:

  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
  

• Never request runtime permissions in AsyncTask.doInBackground()—this method runs on a background thread, and Android requires permission prompts to be triggered from the main thread. Move permission checks to your Activity/Fragment's main lifecycle methods (like onCreate() or onResume()):

  private void checkLocationPermission() {
      if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
          ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1001);
      } else {
          // Permission granted, start location retrieval
          fetchLatestLocation();
      }
  }
  
  // Handle permission grant result
  @Override
  public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
      super.onRequestPermissionsResult(requestCode, permissions, grantResults);
      if (requestCode == 1001 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
          fetchLatestLocation();
      } else {
          Toast.makeText(this, "Location permission is required to get coordinates", Toast.LENGTH_SHORT).show();
      }
  }
  

AsyncTask's doInBackground() is for synchronous background work, but location APIs (especially the updated Google Fused Location Provider) use asynchronous callbacks. Trying to wait for a location in doInBackground() will likely cause deadlocks or missed updates. Instead:

• Use the main thread to initialize the location client and set up callbacks.
• Once you receive the latest location, pass it to an AsyncTask for any follow-up processing (like uploading to a server).

Here's a working example with the Fused Location Provider (compatible with Android 4.0+ if Google Play Services is installed):

private FusedLocationProviderClient fusedLocationClient;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    fusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
    checkLocationPermission();
}

private void fetchLatestLocation() {
    LocationRequest locationRequest = LocationRequest.create();
    locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    locationRequest.setInterval(1000); // Update every 1s
    locationRequest.setFastestInterval(500); // Accept faster updates if available

    fusedLocationClient.requestLocationUpdates(locationRequest, new LocationCallback() {
        @Override
        public void onLocationResult(LocationResult locationResult) {
            super.onLocationResult(locationResult);
            if (locationResult != null && !locationResult.getLocations().isEmpty()) {
                // Get the most recent location
                Location latestLoc = locationResult.getLocations().get(locationResult.getLocations().size() - 1);
                // Pass to AsyncTask for processing
                new LocationProcessingTask().execute(latestLoc);
                // Stop updates to save battery
                fusedLocationClient.removeLocationUpdates(this);
            }
        }
    }, Looper.getMainLooper());
}

// AsyncTask to handle post-location processing (e.g., upload)
private class LocationProcessingTask extends AsyncTask<Location, Void, Void> {
    @Override
    protected Void doInBackground(Location... locations) {
        Location loc = locations[0];
        double latitude = loc.getLatitude();
        double longitude = loc.getLongitude();
        // Do your background work here (e.g., send to server)
        Log.d("LocationData", "Lat: " + latitude + ", Lng: " + longitude);
        return null;
    }
}

If your emulator doesn't have Google Play Services installed (common in older Android 4.0 images), the Fused Location Provider won't work. Fall back to the legacy LocationManager instead:

private void fetchLatestLocationWithLegacyManager() {
    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 0, new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                new LocationProcessingTask().execute(location);
                locationManager.removeUpdates(this);
            }

            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {}

            @Override
            public void onProviderEnabled(String provider) {}

            @Override
            public void onProviderDisabled(String provider) {}
        });
    }
}

• Always mock locations in the Android 4.0 simulator.
• Request runtime permissions only from the main thread.
• Use location callbacks on the main thread, then pass results to AsyncTask for background work.
• Fall back to LocationManager if Google Play Services isn't available on the emulator.

内容的提问来源于stack exchange，提问作者Soul