定期获取位置并绘制标记以映射

Posted 2023-04-14

【中文标题】定期获取位置并绘制标记以映射

【英文标题】：Getting the location periodically and plotting markers to map

【发布时间】：2015-07-14 23:07:21

【问题描述】：

我正在寻找在 android 中创建一个应用程序，该应用程序基本上跟踪手机位置并定期向 google maps api 添加一个标记，以便显示路线，我遇到的问题是我不知道如何定期在后台获取位置。

这是我的代码：

public class MapsActivity extends FragmentActivity implements LocationListener 

private GoogleMap mMap; // Might be null if Google Play services APK is not available.
Button btnCurrent, btnPrevious;
ArrayList<Double> latitude = new ArrayList<>();
ArrayList<Double> longitude = new ArrayList<>();
LocationManager lm;
LocationListener ll;
Location networkLocation;
Location gpsLocation;
double LONG;
double LAT;

@Override
protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);
    lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
    networkLocation = lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
    gpsLocation = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);


    lm.requestLocationUpdates(lm.GPS_PROVIDER, 10, 0, new android.location.LocationListener() 
        @Override
        public void onLocationChanged(Location location) 
            LONG = networkLocation.getLongitude();
            LAT = networkLocation.getLatitude();

            latitude.add(LAT);
            longitude.add(LONG);

            Log.d("COORDS", LAT+" , "+LONG);
        

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

        

        @Override
        public void onProviderEnabled(String provider) 

        

        @Override
        public void onProviderDisabled(String provider) 

        
    );


    setUpMapIfNeeded();




    btnCurrent = (Button)findViewById(R.id.btn_currentLoc);
    btnPrevious = (Button) findViewById(R.id.btn_prevLoc);

    btnCurrent.setOnClickListener(new View.OnClickListener() 
        @Override
        public void onClick(View v) 

            mMap.clear();
            double curLong, curLat;
            String test = lm.getAllProviders().toString();
            LatLng CurrentLoc;

            Log.d("PROVIDERS ", test);

            if((lm.isProviderEnabled("gps"))==true)
            
                curLong = gpsLocation.getLongitude();
                curLat = gpsLocation.getLatitude();
                CurrentLoc = new LatLng(curLat,curLong);
                Log.d("GPS", "true");
            else
            
                curLong = networkLocation.getLongitude();
                curLat = networkLocation.getLatitude();
                CurrentLoc = new LatLng(curLat,curLong);
                Log.d("GPS", "false");
            


            mMap.addMarker(new MarkerOptions().position(new LatLng(curLat,curLong)).title("LOCATION "+ curLat + ", " + curLong));
            mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(CurrentLoc,15));
            Log.d("LOCATION", curLat + "," + curLong);




        
    );

    btnPrevious.setOnClickListener(new View.OnClickListener() 
        @Override
        public void onClick(View v) 


            for(int i = 0;i<latitude.size();i++)
            
                mMap.addMarker(new MarkerOptions().position(new LatLng(latitude.get(i),longitude.get(i))).title("LOCATION "+ latitude.get(i) + ", " + longitude.get(i)));

                Log.d("LOCATION", latitude.get(i)+ "," + longitude.get(i));


            


        
    );



@Override
protected void onResume() 
    super.onResume();
    setUpMapIfNeeded();



private void setUpMapIfNeeded() 
    // Do a null check to confirm that we have not already instantiated the map.
    if (mMap == null) 
        // Try to obtain the map from the SupportMapFragment.
        mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
                .getMap();
        // Check if we were successful in obtaining the map.
        if (mMap != null) 
            setUpMap();
        
    



private void setUpMap() 




private void getCurrentLocation()






private void seeAllLocations()







@Override
public void onLocationChanged(Location location) 

任何帮助将不胜感激。

【问题讨论】：

您是否在 Google 上搜索过如何定期获取位置更新？这是您需要搜索的第一件事，当您找到解决方案时，使用获取的位置放置标记非常容易。我希望你明白我的意思。不要要求完整的解决方案。告诉我们你在实现你的功能时遇到了什么困难。我们很乐意为您提供帮助...

这是您的第一个查询，关于获取位置更新：developer.android.com/training/location/…

【参考方案1】：

检查下面的代码，它可以帮助您获取按钮单击时的当前位置以及@some timeInterval。

public class MainActivity extends Activity implements ConnectionCallbacks,
        OnConnectionFailedListener, LocationListener 

    // LogCat tag
    private static final String TAG = MainActivity.class.getSimpleName();

    private final static int PLAY_SERVICES_RESOLUTION_REQUEST = 1000;

    private Location mLastLocation;

    // Google client to interact with Google API
    private GoogleApiClient mGoogleApiClient;

    // boolean flag to toggle periodic location updates
    private boolean mRequestingLocationUpdates = false;

    private LocationRequest mLocationRequest;

    // Location updates intervals in sec
    private static int UPDATE_INTERVAL = 10000; // 10 sec
    private static int FATEST_INTERVAL = 5000; // 5 sec
    private static int DISPLACEMENT = 10; // 10 meters

    // UI elements
    private TextView lblLocation;
    private Button btnShowLocation, btnStartLocationUpdates;

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

        lblLocation = (TextView) findViewById(R.id.lblLocation);
        btnShowLocation = (Button) findViewById(R.id.btnShowLocation);
        btnStartLocationUpdates = (Button) findViewById(R.id.btnLocationUpdates);

        // First we need to check availability of play services
        if (checkPlayServices()) 

            // Building the GoogleApi client
            buildGoogleApiClient();

            createLocationRequest();
        

        // Show location button click listener
        btnShowLocation.setOnClickListener(new View.OnClickListener() 

            @Override
            public void onClick(View v) 
                displayLocation();
            
        );

        // Toggling the periodic location updates
        btnStartLocationUpdates.setOnClickListener(new View.OnClickListener() 

            @Override
            public void onClick(View v) 
                togglePeriodicLocationUpdates();
            
        );

    

    @Override
    protected void onStart() 
        super.onStart();
        if (mGoogleApiClient != null) 
            mGoogleApiClient.connect();
        
    

    @Override
    protected void onResume() 
        super.onResume();

        checkPlayServices();

        // Resuming the periodic location updates
        if (mGoogleApiClient.isConnected() && mRequestingLocationUpdates) 
            startLocationUpdates();
        
    

    @Override
    protected void onStop() 
        super.onStop();
        if (mGoogleApiClient.isConnected()) 
            mGoogleApiClient.disconnect();
        
    

    @Override
    protected void onPause() 
        super.onPause();
        stopLocationUpdates();
    

    /**
     * Method to display the location on UI
     * */
    private void displayLocation() 

        mLastLocation = LocationServices.FusedLocationApi
                .getLastLocation(mGoogleApiClient);

        if (mLastLocation != null) 
            double latitude = mLastLocation.getLatitude();
            double longitude = mLastLocation.getLongitude();

            lblLocation.setText(latitude + ", " + longitude);

         else 

            lblLocation
                    .setText("(Couldn't get the location. Make sure location is enabled on the device)");
        
    

    /**
     * Method to toggle periodic location updates
     * */
    private void togglePeriodicLocationUpdates() 
        if (!mRequestingLocationUpdates) 
            // Changing the button text
            btnStartLocationUpdates
                    .setText(getString(R.string.btn_stop_location_updates));

            mRequestingLocationUpdates = true;

            // Starting the location updates
            startLocationUpdates();

            Log.d(TAG, "Periodic location updates started!");

         else 
            // Changing the button text
            btnStartLocationUpdates
                    .setText(getString(R.string.btn_start_location_updates));

            mRequestingLocationUpdates = false;

            // Stopping the location updates
            stopLocationUpdates();

            Log.d(TAG, "Periodic location updates stopped!");
        
    

    /**
     * Creating google api client object
     * */
    protected synchronized void buildGoogleApiClient() 
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API).build();
    

    /**
     * Creating location request object
     * */
    protected void createLocationRequest() 
        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(UPDATE_INTERVAL);
        mLocationRequest.setFastestInterval(FATEST_INTERVAL);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationRequest.setSmallestDisplacement(DISPLACEMENT);
    

    /**
     * Method to verify google play services on the device
     * */
    private boolean checkPlayServices() 
        int resultCode = GooglePlayServicesUtil
                .isGooglePlayServicesAvailable(this);
        if (resultCode != ConnectionResult.SUCCESS) 
            if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) 
                GooglePlayServicesUtil.getErrorDialog(resultCode, this,
                        PLAY_SERVICES_RESOLUTION_REQUEST).show();
             else 
                Toast.makeText(getApplicationContext(),
                        "This device is not supported.", Toast.LENGTH_LONG)
                        .show();
                finish();
            
            return false;
        
        return true;
    

    /**
     * Starting the location updates
     * */
    protected void startLocationUpdates() 

        LocationServices.FusedLocationApi.requestLocationUpdates(
                mGoogleApiClient, mLocationRequest, this);

    

    /**
     * Stopping location updates
     */
    protected void stopLocationUpdates() 
        LocationServices.FusedLocationApi.removeLocationUpdates(
                mGoogleApiClient, this);
    

    /**
     * Google api callback methods
     */
    @Override
    public void onConnectionFailed(ConnectionResult result) 
        Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = "
                + result.getErrorCode());
    

    @Override
    public void onConnected(Bundle arg0) 

        // Once connected with google api, get the location
        displayLocation();

        if (mRequestingLocationUpdates) 
            startLocationUpdates();
        
    

    @Override
    public void onConnectionSuspended(int arg0) 
        mGoogleApiClient.connect();
    

    @Override
    public void onLocationChanged(Location location) 
        // Assign the new location
        mLastLocation = location;

        Toast.makeText(getApplicationContext(), "Location changed!",
                Toast.LENGTH_SHORT).show();

        // Displaying the new location on UI
        displayLocation();