使用 Google Maps Android API v2 在 Google Maps 上绘制路线

Question

我有一个应用程序，我在其中使用 Google Plays 新服务 API for Maps 持续跟踪用户的位置。我每秒钟都在更新位置，并且我还在检查用户活动，如静止、倾斜、车内等，以获得更好的位置跟踪。我可以使用我的代码绘制路径，但它不准确，并且与用户实际驾驶/行走的道路有很大不同。它总是在远离实际用户路径的地方画线。

我的服务：-

public class MyService extends Service implements LocationListener {

    private final Context mContext;
    private static MyService mInstance = null;
    private final static String TAG = "RidingTimerService";

    boolean isGPSEnabled = false;

    private long mStartTime = 0L;
    private long timeInMilliseconds = 0L;
    private long timeSwapBuff = 0L;
    private long updatedTime = 0L;
    private Handler mHandler = null;
    private int mHours = 0;

    // Declaring a Location Manager
    private LocationManager mLocationManager = null;
    private Location mCurrentLocation = null; // location
    private double[][] positions;
    private long[] times;
    private final Integer data_points = 2; // how many data points to calculate
    private double mTravelledDistance = 0.0f;

    private SharedPreferences mPreferences = null;
    private ArrayList<LatLng> mDirectionsPoints = new ArrayList<LatLng>();

    public boolean mIsPhoneMoving = false;
    public int mActivityType = -1;
    int counter = 0;

    private IntentFilter mBroadcastFilter;
    private DetectionRequester mDetectionRequester;
    private DetectionRemover mDetectionRemover;

    public MyService() {
        mContext = this;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mInstance = this;
        // two arrays for position and time.
        positions = new double[data_points][2];
        times = new long[data_points];

        mStartTime = SystemClock.uptimeMillis();
        mHandler = new Handler();
        mHandler.postDelayed(countDownTimerThread, 0);
        mPreferences = getSharedPreferences(MyPreferences.PREFERENCES,
                Context.MODE_PRIVATE);
        // Create a new Intent filter for the broadcast receiver
        mBroadcastFilter = new IntentFilter(
                MyConstants.ACTION_REFRESH_STATUS_LIST);
        mBroadcastFilter.addCategory(MyConstants.CATEGORY_LOCATION_SERVICES);

        // Get detection requester and remover objects
        mDetectionRequester = new DetectionRequester(this);
        mDetectionRemover = new DetectionRemover(this);
        mDirectionsPoints.clear();
    }

    /**
     * Pause the timer
     */
    public void pauseRide() {
        timeSwapBuff += timeInMilliseconds;
        mHandler.removeCallbacks(countDownTimerThread);
        mLocationManager.removeUpdates(this);
    }

    /**
     * Restart the timer
     */
    public void reStartRide() {
        mStartTime = SystemClock.uptimeMillis();
        mHandler.postDelayed(countDownTimerThread, 0);
        mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
                0, 0, this);
    }

    @Override
    public void onDestroy() {
        mHandler.removeCallbacks(countDownTimerThread);
        mLocationManager.removeUpdates(this);
        super.onDestroy();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        getLocation();
        return super.onStartCommand(intent, flags, startId);
    }

    /**
     * Timer thread
     */
    private final Runnable countDownTimerThread = new Runnable() {

        public void run() {
            mHours = 0;
            timeInMilliseconds = SystemClock.uptimeMillis() - mStartTime;
            updatedTime = timeSwapBuff + timeInMilliseconds;
            int secs = (int) (updatedTime / 1000);
            final int mins = secs / 60;
            mHours = mins / 60;
            secs = secs % 60;

            final Message msg = new Message();
            final Bundle bundle = new Bundle();
            bundle.putInt(MyPreferences.BROADCAST_CODES, 300);
            bundle.putString(
                    "time",
                    String.format("%02d", mHours) + ":"
                            + String.format("%02d", mins) + ":"
                            + String.format("%02d", secs));
            msg.setData(bundle);
            final Intent intent = new Intent(MyConstants.BROADCAST_INTENT);
            intent.putExtras(bundle);
            sendBroadcast(intent);
            mHandler.postDelayed(this, 1000);
        }
    };

    @Override
    public IBinder onBind(final Intent intent) {
        return null;
    }

    @Override
    public void onLocationChanged(final Location location) {
        if (location != null) {
            LocationUtils.sLatitude = location.getLatitude();
            LocationUtils.sLongitude = location.getLongitude();

            mDirectionsPoints.add(new LatLng(LocationUtils.sLatitude,
                    LocationUtils.sLongitude));
            riderLocation(location);
        } else {
            Log.i(TAG, "Location is not available.");
        }
    }

    /**
     * Calculate speed, distance and average speed. Send Broadcast which
     * received by activities
     * 
     * @param location
     */
    private void riderLocation(final Location location) {
        DecimalFormat formatter = new DecimalFormat("#0.00");
        double distance = 0.0;
        Double speed = 0.0;
        long t1 = 0l;
        final float[] results = new float[3];

        positions[counter][0] = location.getLatitude();
        positions[counter][1] = location.getLongitude();
        times[counter] = location.getTime();

        final Bundle bundle = new Bundle();
        bundle.putInt(MyPreferences.BROADCAST_CODES, 200);

        distance = calculateDistance(positions[counter][0],
                positions[counter][1], positions[(counter + (data_points - 1))
                        % data_points][0],
                positions[(counter + (data_points - 1)) % data_points][1]);

        Location.distanceBetween(positions[counter][0], positions[counter][1],
                positions[(counter + (data_points - 1)) % data_points][0],
                positions[(counter + (data_points - 1)) % data_points][1],
                results);

        mTravelledDistance += results[0] / 1000;
        LocationUtils.sDistance = formatter
                .format((mTravelledDistance * 100.0) / 100.0);

        final double averageSpeed = mTravelledDistance / mHours;
        LocationUtils.sAverageSpeed = formatter
                .format((averageSpeed * 100.0) / 100.0);

        if (location.hasSpeed()) {
            speed = location.getSpeed() * 3.6;
            LocationUtils.sSpeed = speed.intValue();
        } else {
            try {
                t1 = times[counter]
                        - times[(counter + (data_points - 1)) % data_points];
            } catch (final NullPointerException e) {
                // all good, just not enough data yet.
            }

            speed = (distance / t1) * 3.6;
            LocationUtils.sSpeed = speed.intValue();
            counter = (counter + 1) % data_points;
        }

        LocationUtils.sLatitude = location.getLatitude();
        LocationUtils.sLongitude = location.getLongitude();

        final Intent intent = new Intent(MyConstants.BROADCAST_INTENT);
        intent.putExtras(bundle);
        sendBroadcast(intent);
    }

    public void onProviderDisabled(final String arg0) {
        Toast.makeText(getApplicationContext(), "Gps Disabled",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderEnabled(final String arg0) {
        Toast.makeText(getApplicationContext(), "Gps Enabled",
                Toast.LENGTH_SHORT).show();
    }

    /**
     * @return location
     */
    public Location getLocation() {
        try {
            mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

            // getting GPS status
            isGPSEnabled = mLocationManager
                    .isProviderEnabled(LocationManager.GPS_PROVIDER);

            if (!isGPSEnabled) {
                // no network provider is enabled
                showSettingsAlert();
            } else {
                // if GPS Enabled get lat/long using GPS Services
                if (isGPSEnabled) {
                    mLocationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER, 0, 0, this);
                    Log.d(TAG, "GPS Enabled");
                    if (mCurrentLocation == null) {
                        if (mLocationManager != null) {
                            mCurrentLocation = mLocationManager
                                    .getLastKnownLocation(LocationManager.GPS_PROVIDER);

                            if (mCurrentLocation != null) {
                                LocationUtils.sLatitude = mCurrentLocation
                                        .getLatitude();
                                LocationUtils.sLongitude = mCurrentLocation
                                        .getLongitude();
                            }
                        }
                    } else {
                        LocationUtils.sLatitude = mCurrentLocation
                                .getLatitude();
                        LocationUtils.sLongitude = mCurrentLocation
                                .getLongitude();
                    }
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return mCurrentLocation;
    }

    /**
     * @fn public static RidingTimerService getInstance()
     * @brief returns instance of the service.
     * @return RidingTimerService instance
     */
    public static MyService getInstance() {
        return mInstance;
    }

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

    /**
     * Reset all the values stored in Preferences
     */
    public void resetAllText() {
        mPreferences.edit().putString(MyPreferences.LATITUDE, "0.0").commit();
        mPreferences.edit().putString(MyPreferences.LONGITUDE, "0.0")
                .commit();
        mPreferences.edit().putString(MyPreferences.SPEED, "0.0").commit();
        mPreferences.edit().putString(MyPreferences.AVERAGE_SPEED, "0.0")
                .commit();
        mPreferences.edit().putString(MyPreferences.DISTANCE, "0.0").commit();
    }

    /**
     * Respond to "Start" button by requesting activity recognition updates.
     * 
     * @param view
     *            The view that triggered this method.
     */
    public void onStartUpdates() {
        // Pass the update request to the requester object
        mDetectionRequester.requestUpdates();
    }

    /**
     * Respond to "Stop" button by canceling updates.
     * 
     * @param view
     *            The view that triggered this method.
     */
    public void onStopUpdates() {
        // Pass the remove request to the remover object
        mDetectionRemover.removeUpdates(mDetectionRequester
                .getRequestPendingIntent());

        /*
         * Cancel the PendingIntent. Even if the removal request fails,
         * canceling the PendingIntent will stop the updates.
         */
        mDetectionRequester.getRequestPendingIntent().cancel();
    }

    /**
     * Function to show settings alert dialog On pressing Settings button will
     * lauch Settings Options
     * */
    public void showSettingsAlert() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
        alertDialog.setTitle("GPS");
        alertDialog.setMessage("GPS is not enabled. Do you want to enable it?");

        // On pressing Settings button
        alertDialog.setPositiveButton("Settings",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        Intent intent = new Intent(
                                Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                        mContext.startActivity(intent);
                    }
                });

        // on pressing cancel button
        alertDialog.setNegativeButton("Cancel",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });

        // Showing Alert Message
        alertDialog.show();
    }

    /**
     * @return List of Direction points
     */
    public ArrayList<LatLng> getDirectionsPoints() {
        if (mDirectionsPoints != null) {
            return mDirectionsPoints;
        } else {
            mDirectionsPoints = new ArrayList<LatLng>();
            return mDirectionsPoints;
        }
    }

    /**
     * Calculate distance
     * 
     * @param lat1
     * @param lon1
     * @param lat2
     * @param lon2
     * @return
     */
    private double calculateDistance(final double lat1, final double lon1,
            final double lat2, final double lon2) {
        // haversine great circle distance approximation, returns meters
        final double theta = lon1 - lon2;
        double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2))
                + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2))
                * Math.cos(deg2rad(theta));
        dist = Math.acos(dist);
        dist = rad2deg(dist);
        dist = dist * 60; // 60 nautical miles per degree of seperation
        dist = dist * 1852; // 1852 meters per nautical mile
        return dist;
    }

    private double deg2rad(final double deg) {
        return (deg * Math.PI / 180.0);
    }

    private double rad2deg(final double rad) {
        return (rad * 180.0 / Math.PI);
    }
}

我每 1 秒更新一次位置，每 3 秒更新一次活动识别。我能够获取位置，但在 Google 地图中未正确绘制路径。

绘制路径的代码：-

public class MapsActivity extends FragmentActivity {

    private static GoogleMap mGoogleMap = null;
    private static final String TAG = "MapsActivity";
    private Button mBtnStartRide, mBtnPauseRide, mBtnStopRide = null;
    private static TextView mTxtLatLong, mTxtTimer, mTxtTotalSize,
            mTxtSpeed = null;
    private static PolylineOptions mPolyLineOptions = null;
    // Storing the directions returned by the direcction api
    private SharedPreferences mPreferences = null;
    private MapsBroadcastReceiver receiver = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        receiver = new MapsBroadcastReceiver();
        mPreferences = getSharedPreferences(TestPreferences.PREFERENCES,
                Context.MODE_PRIVATE);

        mTxtLatLong = (TextView) findViewById(R.id.txtLatLong);
        mTxtTimer = (TextView) findViewById(R.id.txtTimer);
        mTxtTotalSize = (TextView) findViewById(R.id.txtDirectionsSize);
        mTxtSpeed = (TextView) findViewById(R.id.txtSpeed);

        mBtnStartRide = (Button) findViewById(R.id.btn_start_ride);
        mBtnPauseRide = (Button) findViewById(R.id.btn_pause_ride);
        mBtnStopRide = (Button) findViewById(R.id.btn_stop_ride);

        final Button mBtnCenter = (Button) findViewById(R.id.btn_center);
        mBtnCenter.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                animateCameraTo();
            }
        });

        mBtnStartRide.setOnClickListener(btnStartRideClickListener);
        mBtnPauseRide.setOnClickListener(btnPauseRideClickListener);
        mBtnStopRide.setOnClickListener(btnStopRideClickListener);

        initilizeMap();
    }

    /**
     * Start Ride Button Click Listener
     */
    private OnClickListener btnStartRideClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            if (mPreferences.getBoolean(TestPreferences.IS_RIDE_PAUSE, false)) {
                if (MyService.getInstance() != null) {
                    MyService.getInstance().reStartRide();
                }
            } else {
                startService(new Intent(MapsActivity.this,
                        MyService.class));
            }

            mPreferences.edit().putBoolean(TestPreferences.IS_RIDE_START, true)
                    .commit();
            mPreferences.edit().remove(TestPreferences.IS_RIDE_PAUSE).commit();
            mPreferences.edit().remove(TestPreferences.IS_RIDE_STOPPED)
                    .commit();

            mBtnStartRide.setVisibility(View.GONE);
            mBtnPauseRide.setVisibility(View.VISIBLE);
            mBtnStopRide.setVisibility(View.VISIBLE);
        }
    };

    /**
     * Start Ride Button Click Listener
     */
    private OnClickListener btnPauseRideClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            MyService.getInstance().pauseRide();

            mPreferences.edit().putBoolean(TestPreferences.IS_RIDE_PAUSE, true)
                    .commit();
            mPreferences.edit()
                    .putBoolean(TestPreferences.IS_RIDE_START, false).commit();
            mBtnStartRide.setVisibility(View.VISIBLE);
            mBtnPauseRide.setVisibility(View.GONE);
            mBtnStopRide.setVisibility(View.VISIBLE);
        }
    };

    /**
     * Stop Ride Button Click Listener
     */
    private OnClickListener btnStopRideClickListener = new OnClickListener() {

        @Override
        public void onClick(View v) {
            stopService(new Intent(MapsActivity.this, MyService.class));
            mPreferences.edit().remove(TestPreferences.IS_RIDE_PAUSE).commit();
            mPreferences.edit()
                    .putBoolean(TestPreferences.IS_RIDE_START, false).commit();
            mPreferences.edit()
                    .putBoolean(TestPreferences.IS_RIDE_STOPPED, true).commit();
            mBtnStartRide.setVisibility(View.VISIBLE);
            mBtnPauseRide.setVisibility(View.GONE);
            mBtnStopRide.setVisibility(View.GONE);
        }
    };

    @Override
    protected void onResume() {
        super.onResume();
        registerReceiver(receiver, new IntentFilter(
                MyConstants.BROADCAST_INTENT));
        initilizeMap();

        if (mPreferences.getBoolean(TestPreferences.IS_RIDE_START, false)) {
            mBtnStartRide.setVisibility(View.GONE);
            mBtnPauseRide.setVisibility(View.VISIBLE);
            mBtnStopRide.setVisibility(View.VISIBLE);
        } else if (mPreferences
                .getBoolean(TestPreferences.IS_RIDE_PAUSE, false)) {
            mBtnStartRide.setVisibility(View.VISIBLE);
            mBtnPauseRide.setVisibility(View.GONE);
            mBtnStopRide.setVisibility(View.VISIBLE);
        } else if (mPreferences.getBoolean(TestPreferences.IS_RIDE_STOPPED,
                false)) {
            // Show start button and gone Pause & Stop both
            mBtnStartRide.setVisibility(View.VISIBLE);
            mBtnPauseRide.setVisibility(View.GONE);
            mBtnStopRide.setVisibility(View.GONE);
        } else {
            // Show start button and gone Pause & Stop both
            mBtnStartRide.setVisibility(View.VISIBLE);
            mBtnPauseRide.setVisibility(View.GONE);
            mBtnStopRide.setVisibility(View.GONE);
        }

        setAllText();
    }

    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(receiver);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        mGoogleMap = null;
    }

    /**
     * Function to load map. If map is not created it will create it for you
     * */
    private void initilizeMap() {
        if (mGoogleMap == null) {
            mGoogleMap = ((MapFragment) getFragmentManager().findFragmentById(
                    R.id.map)).getMap();
            // check if map is created successfully or not
            if (mGoogleMap == null) {
                Toast.makeText(getApplicationContext(),
                        "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                        .show();
            } else {
                mPolyLineOptions = new PolylineOptions().width(6).color(
                        Color.BLUE);
                mGoogleMap.setTrafficEnabled(true);
                mGoogleMap.getUiSettings().setMyLocationButtonEnabled(true);
                mGoogleMap.getUiSettings().setRotateGesturesEnabled(true);
                mGoogleMap.getUiSettings().setCompassEnabled(true);
                mGoogleMap.getUiSettings().setZoomGesturesEnabled(true);
                mGoogleMap.getUiSettings().setZoomControlsEnabled(true);

                if (MyService.getInstance() != null
                        && MyService.getInstance().getDirectionsPoints() != null
                        && !MyService.getInstance().getDirectionsPoints()
                                .isEmpty()
                        && MyService.getInstance().getDirectionsPoints()
                                .size() >= 1) {
                    mGoogleMap.addMarker(new MarkerOptions()
                            .position(
                                    MyService.getInstance()
                                            .getDirectionsPoints().get(0))
                            .anchor(0.8f, 1.0f).title("Your Location"));

                    animateCameraTo(MyService.getInstance()
                            .getDirectionsPoints().get(0).latitude,
                            MyService.getInstance().getDirectionsPoints()
                                    .get(0).longitude);
                }
            }
        } else {
            mPolyLineOptions = new PolylineOptions().width(6).color(Color.BLUE);
            mGoogleMap.getUiSettings().setMyLocationButtonEnabled(true);
            mGoogleMap.getUiSettings().setRotateGesturesEnabled(true);
            mGoogleMap.getUiSettings().setCompassEnabled(true);
            mGoogleMap.getUiSettings().setZoomGesturesEnabled(true);
            mGoogleMap.getUiSettings().setZoomControlsEnabled(true);

            if (MyService.getInstance() != null
                    && MyService.getInstance().getDirectionsPoints() != null
                    && !MyService.getInstance().getDirectionsPoints()
                            .isEmpty()
                    && MyService.getInstance().getDirectionsPoints().size() >= 1) {

                Log.i(TAG, "Lat long in resume2222222222 = "
                        + MyService.getInstance().getDirectionsPoints()
                                .get(0).latitude
                        + ", "
                        + MyService.getInstance().getDirectionsPoints()
                                .get(0).longitude);

                mGoogleMap.addMarker(new MarkerOptions()
                        .position(
                                MyService.getInstance().getDirectionsPoints()
                                        .get(0)).anchor(0.8f, 1.0f)
                        .title("Your Location"));

                animateCameraTo(MyService.getInstance().getDirectionsPoints()
                        .get(0).latitude, MyService.getInstance()
                        .getDirectionsPoints().get(0).longitude);
            }
        }
    }

    /**
     * @author Scorpion
     * 
     */
    private class MapsBroadcastReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {

            switch (intent.getExtras().getInt(TestPreferences.BROADCAST_CODES)) {
            case 100:
                showErrorDialog(intent.getExtras().getInt(
                        TestPreferences.BROADCAST_CODES));
                break;

            case 200:
                setAllText();
                break;

            case 300:
                if (intent.getExtras().getString("time") != null) {
                    mTxtTimer.setText("Timer - "
                            + intent.getExtras().getString("time"));
                } else {
                    mTxtTimer.setText("Timer - 00:00:00");
                }
                break;

            default:
                break;
            }

            if (MyService.getInstance() != null
                    && !MyService.getInstance().getDirectionsPoints()
                            .isEmpty()
                    && MyService.getInstance().getDirectionsPoints().size() == 1) {
                mGoogleMap.addMarker(new MarkerOptions()
                        .position(
                                MyService.getInstance().getDirectionsPoints()
                                        .get(0)).anchor(0.8f, 1.0f)
                        .title("Your Location"));
            }

        }
    }

    /**
     * 
     */
    public void setAllText() {
        mTxtLatLong.setText("Lat - " + LocationUtils.sLatitude + ", Lng - "
                + LocationUtils.sLongitude);

        mTxtSpeed.setText("Speed - " + LocationUtils.sSpeed);
        mTxtTotalSize.setText("Distance - " + LocationUtils.sDistance);
    }

    /**
     * Animate to position on Google Maps
     * 
     * @param lat
     * @param lng
     */
    private void animateCameraTo() {
        // Saving the points in a polyline

        if (MyService.getInstance() != null
                && MyService.getInstance().getDirectionsPoints() != null
                && !MyService.getInstance().getDirectionsPoints().isEmpty()) {
            mPolyLineOptions.geodesic(true);
            mPolyLineOptions.addAll(MyService.getInstance()
                    .getDirectionsPoints());

            // Drawing the path on the map Polyline route =
            mGoogleMap.addPolyline(mPolyLineOptions);

            int index = MyService.getInstance().getDirectionsPoints().size() - 1;
            CameraPosition cameraPosition = new CameraPosition.Builder()
                    .target(MyService.getInstance().getDirectionsPoints()
                            .get(index)).zoom(20).build();

            mGoogleMap.animateCamera(CameraUpdateFactory
                    .newCameraPosition(cameraPosition));
        }

    }

    /**
     * Animate to position on Google Maps
     * 
     * @param lat
     * @param lng
     */
    private void animateCameraTo(final double lat, final double lng) {
        // Saving the points in a polyline
        if (MyService.getInstance() != null
                && MyService.getInstance().getDirectionsPoints() != null
                && !MyService.getInstance().getDirectionsPoints().isEmpty()) {
            mPolyLineOptions.geodesic(true);
            mPolyLineOptions.addAll(MyService.getInstance()
                    .getDirectionsPoints());

            // Drawing the path on the map
            mGoogleMap.addPolyline(mPolyLineOptions);
            CameraPosition cameraPosition = new CameraPosition.Builder()
                    .target(new LatLng(lat, lng)).zoom(20).build();

            mGoogleMap.animateCamera(CameraUpdateFactory
                    .newCameraPosition(cameraPosition));
        }

    }

    /**
     * Show a dialog returned by Google Play services for the connection error
     * code
     * 
     * @param errorCode
     *            An error code returned from onConnectionFailed
     */
    private void showErrorDialog(int errorCode) {

        // Get the error dialog from Google Play services
        Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog(errorCode,
                MapsActivity.this,
                LocationUtils.CONNECTION_FAILURE_RESOLUTION_REQUEST);

        // If Google Play services can provide an error dialog
        if (errorDialog != null) {

            // Create a new DialogFragment in which to show the error dialog
            ErrorDialogFragment errorFragment = new ErrorDialogFragment();

            // Set the dialog in the DialogFragment
            errorFragment.setDialog(errorDialog);

            // Show the error dialog in the DialogFragment
            errorFragment.show(getSupportFragmentManager(),
                    LocationUtils.APPTAG);
        }
    }
}

从位置提供者获得的坐标结果：- 23.030392522689674，72.5570888165469，23.030408166940184，72.55708600340783，23.030451207802273，72.55708215400317，23.030448342522195，72.5570607428365，23.03045605637773，72.55702903413072，23.03046687434995，72.55702007867455，23.030481227996425，72.55702017125606，23.03049188235562，72.55701618151457，23.030501580461667，72.55701051075931，23.030506644074638，72.55700568837983，23.030510243171772，72.55699463185964，23.03051656621021，72.55698811382064，23.030523584332027， 72.55698589863236，23.030527893257556，72.5569835596，23.03052731568596，72.55698681171178，23.030533706759005，72.55699683791043，23.03053795413862，72.5570022232021，23.03054422659466，72.55700788646914，23.030550353227323，72.5570133047868，23.03056167617575，72.5570171806126，23.030572274532982，72.55702744953462，23.03057623596164，72.55703687229187，23.03058756510295，72.55703589208271，23.030591797598742，72.5570396833694，23.030597556470788，72.55703954449652， 23.030602030769657, 72.55704359454182, 23.030 606735158617，72.55704993131606，23.030611670633565，72.55705060538087,23.030618875802222，72.55705181604097，23.030629137631596，72.55705043471286，23.030651405170016，72.55705440295588，23.03066642161307，72.55705285209174，23.030690454277963，72.55703884780276，23.030708214416187，72.55703489882957，23.03072341369183，72.5570340196122，23.030737371000015，72.55703289416898，23.03075088423441，72.55703750535102，23.030767572625837，72.55704489874579，23.030794398930176， 72.55703870239826，23.03081655932613，72.55702474270966，23.030827505666753，72.5570121351611，23.03083720431765，72.55700390084714，23.03084624667527，72.55700122660554，23.030859495795887，72.55699948514881，23.030870357210333，72.55699625144317，23.030881843633054

Answer 1

此代码将起作用

GoogleMap map;
   // ... get a map.
   // Add a thin red line from London to New York.
   Polyline line = map.addPolyline(new PolylineOptions()
       .add(new LatLng(51.5, -0.1), new LatLng(40.7, -74.0))
       .width(5)
       .color(Color.RED));

Answer 2

您应该将您的问题分解为数据收集和数据显示方面。

因此，取两个您确切知道的坐标并在谷歌地图上绘制一条直线折线。 如果它真的显示在错误的位置，GoogleMap 确实有一个错误，顺便说一句我不相信。

然后打印出您的坐标，例如在绘制它们之前到 LogCat 并检查坐标。如果他们错了，这不是 GoogleMaps 的问题，而是 LocationProvider 或您如何使用它的问题。

如果坐标收集正确，您可以通过某种方式从 LogCat 中提取它们并直接在代码中使用它们来绘制折线。如果然后折线被移位，您可能又在 GoogleMap 中发现了一个错误。然后你应该在这里粘贴坐标，以便有人可以复制它。它可能取决于设备。我从来没有与地图不匹配的折线。

Answer 3

您绘制路径的代码看起来很奇怪。 在for-loop 内，您应该只将点添加到PolylineOptions 的实例（您在进入for 循环之前创建）。

然后，在for-loop 之后，您可以将width、color 等添加到polylineOptions object，最后在mGoogleMap.addPolyline() 中使用。

在您的编码中，您以某种方式为每个点添加了一个新的polyline（我想知道这是否会画线，因为每条“线”仅包含一个点。）。