Android根据用户的位置从sqlite获取附近的纬度经度

Question

我正在创建一个由谷歌地图和地图下地点列表视图组成的应用程序。我决定添加一个按钮，如果用户单击它，附近的位置将根据用户在列表视图中的位置出现，并且标记将出现在地图中。我不知道该怎么做。请帮帮我。

public class MainActivity extends AppCompatActivity implements LocationListener {

GoogleMap map;

List<LocationModel> GetLocation;
Context context = this;
DatabaseHelper dbhelper;
DatabaseHelper db = new DatabaseHelper(this);
ListView lv;
View yourListView,yourProfileView;
Button button;



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

    dbhelper = new DatabaseHelper(MainActivity.this);


    button = (Button) findViewById(R.id.button);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View convertView) {

            findNearByPlaces();

        }

    });

    try{
        dbhelper.createDataBase();
    }
    catch(IOException e){
        e.printStackTrace();
    }
    try {
        dbhelper.openDataBase();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    GetLocation = dbhelper.getLocation();
    lv = (ListView) findViewById(R.id.listView);
    lv.setAdapter(new ViewAdapter());

    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

            LatLng latlngtofocus = new LatLng(Double.parseDouble(GetLocation.get(i).getlatitude()),  Double.parseDouble(GetLocation.get(i).getlongitude()));

            map.animateCamera(CameraUpdateFactory.newLatLngZoom(latlngtofocus, 17.0f));

            MarkerOptions markerOptions = new MarkerOptions();
            markerOptions.position(latlngtofocus);
            //adding marker to the map
            map.addMarker(markerOptions);


            yourListView = findViewById(R.id.layout);
            ViewGroup parent = (ViewGroup) yourListView.getParent();
            parent.removeView(yourListView);
            // inflate your profile view (or get the reference to it if it's already inflated)
            yourProfileView = getLayoutInflater().inflate(R.layout.profile_location, parent, false);
            // add it to the parent
            parent.addView(yourProfileView);

        }


    });



    //To get MapFragment reference from xml layout
    MapFragment mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.map);

    //To get map object
    map = mapFragment.getMap();
    map.getUiSettings().setZoomControlsEnabled(true);

   /* //to show current location in the map
    map.setMyLocationEnabled(true);

    map.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
        @Override
        public void onMapClick(LatLng latLng) {

            Toast.makeText(getApplicationContext(), latLng.toString(), Toast.LENGTH_LONG).show();
        }
    });*/

    //To setup location manager
    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    //To request location updates
    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 1, 1, this);

}

private void findNearByPlaces() {
    Location mLastLocation = new LatLng(location.getLatitude(), location.getLongitude()); //ERROR

    long currentLat = mLastLocation.getLatitude(); //ERROR
    long currentLng = mLastLocation.getLongitude(); //ERROR

    List<LocationModel> nearByLocationList = new ArrayList<LocationModel>();
    for(int i =0 ; i< GetLocation.size(); i++ ){
        if(isInRange(currentLat,currentLng,GetLocation.getlat(),
                GetLocation.getLong())){//ERROR
            nearByLocationList.add(GetLocation.get(i));
        }
    }
    showDataOnMap(nearByLocationList);
}

private boolean isInRange(long currentLat, long currentlongi,long databaseLat, long databaselongi)
{
    Location loc1 = new Location(currentLat,currentlongi); loc1.setLatitude(lat1);//ERROR
    loc1.setLongitude(lon1);
    Location loc2 = new Location(databaseLat, databaselongi); loc2.setLatitude(lat2);//ERROR
    loc2.setLongitude(lon2);
    float distanceInMeters = loc1.distanceTo(loc2);
    if(distanceInMeters <= 50)// your given range
        return true;
    else
        return false;
}

private void showDataOnMap(List<LocationModel> nearByLocationList){
    for(int i =0 ; i< nearByLocationList.size(); i++){
        LatLng latlngtofocus = new      LatLng(Double.parseDouble(nearByLocationList.get(i).getlatitude()),     Double.parseDouble(nearByLocationList.get(i).getlongitude()));

        map.animateCamera(CameraUpdateFactory.newLatLngZoom(latlngtofocus, 17.0f));

        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(latlngtofocus);
        //adding marker to the map
        map.addMarker(markerOptions);
    }
}
@Override
public void onLocationChanged(Location location) {

    //To clear map data
    map.clear();

    //To hold location
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());

    //To create marker in map
    MarkerOptions markerOptions = new MarkerOptions();
    markerOptions.position(latLng);
    markerOptions.title("My Location");
    //adding marker to the map
    map.addMarker(markerOptions);

    //opening position with some zoom level in the map
    map.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 17.0f));
}

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

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}

/****************************************************************************************
 *                                      CUSTOM LIST
 ****************************************************************************************/
public class ViewAdapter extends BaseAdapter {

    LayoutInflater mInflater;

    public ViewAdapter() {
        mInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return GetLocation.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.item_country,null);
        }

        final TextView location = (TextView) convertView.findViewById(R.id.location);
        final TextView latitude = (TextView) convertView.findViewById(R.id.latitude);
        final TextView longitude = (TextView) convertView.findViewById(R.id.longitude);

        location.setText(GetLocation.get(position).getlocation());
        latitude.setText(GetCountry.get(position).getlatitude());
        longitude.setText(GetCountry.get(position).getlongitude());

        return convertView;
    }
}

@Override
public void onBackPressed() {
    if(yourProfileView != null && yourProfileView.getParent() != null) {
        // remove your profile view
        ViewGroup parent = (ViewGroup) yourProfileView.getParent();
        parent.removeView(yourProfileView);

        // a reference to yourListView has to be saved somewhere; just get it

        // add your listview to the parent
        parent.addView(yourListView);
    } else {
        super.onBackPressed();
    }
}

}

Answer 1

button.setOnClickListener(){

   findNearByPlaces();
}

private void findNearByPlaces(){
Location mLastLocation =//http://developer.android.com/training/location/retrieve-current.html
 long currentLat = mLastLocation.getLatitude();
  long currentLng = mLastLocation.getLongitude();

List<LocationModel> nearByLocationList = new ArrayList<LocationModel>();
for(int i =0 ; i< GetLocation.size(); i++ ){
      if(isInRange(currentLat,currentLng,GetLocation.getlat(),
            GetLocation.getLong())){
                     nearByLocationList.add(GetLocation.get(i));
      }
 }

   showDataOnMap(nearByLocationList);
}

private boolean isInRange(long currentLat, long currentlongi,long databaseLat, long databaselongi)
{ 
Location loc1 = new Location(currentLat,currentlongi); loc1.setLatitude(lat1); 
loc1.setLongitude(lon1); 
Location loc2 = new Location(databaseLat, databaselongi); loc2.setLatitude(lat2); 
loc2.setLongitude(lon2); 
float distanceInMeters = loc1.distanceTo(loc2);
if(distanceInMeters <= 50)// your given range
 return true;
else 
 return false;
} 


private void showDataOnMap(List<LocationModel> nearByLocationList){
for(int i =0 ; i< nearByLocationList.size(); i++){
    LatLng latlngtofocus = new      LatLng(Double.parseDouble(nearByLocationList.get(i).getlatitude()),     Double.parseDouble(nearByLocationList.get(i).getlongitude()));

                map.animateCamera(CameraUpdateFactory.newLatLngZoom(latlngtofocus, 17.0f));

                MarkerOptions markerOptions = new MarkerOptions();
                markerOptions.position(latlngtofocus);
                //adding marker to the map 
                map.addMarker(markerOptions);
}
}

Answer 2

不要删除列表视图。只需setVisibilty(View.GONE)。