場所が変更されたときに、Googleマップのapiのテキストビューが更新されない

Question

マップの上のテキストビューに、緯度、経度、速度、および距離を表示するアプリがあります。最初の場所が表示されますが、別の場所に移動すると、テキストビューは情報を更新しません。私は距離を正しく計算しているかどうかもわかりません。 onLocationChangedが呼び出されたかどうかはわかりません。私のコードは以下の通りです。これはすぐにロケーションサービスを停止しますので、あなたにonLocationChnage()ができません呼び出す

if (mGoogleApiClient != null) { 
     LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
    } 

：これを削除

：あなたのonLocationChanged()方法で

public class MainActivity extends AppCompatActivity 
     implements OnMapReadyCallback, 
     GoogleApiClient.ConnectionCallbacks, 
     GoogleApiClient.OnConnectionFailedListener, 
     LocationListener { 

    GoogleMap mGoogleMap; 
    SupportMapFragment mapFrag; 
    LocationRequest mLocationRequest; 
    GoogleApiClient mGoogleApiClient; 
    Location mLastLocation; 
    Marker mCurrLocationMarker; 
    private ArrayList<Location> locations = new ArrayList<Location>(); 

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

     getSupportActionBar().setTitle("Map"); 

     mapFrag = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map); 
     mapFrag.getMapAsync(this); 
    } 

    @Override 
    public void onPause() { 
     super.onPause(); 

     //stop location updates when Activity is no longer active 
     if (mGoogleApiClient != null) { 
      LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
     } 
    } 

    @Override 
    public void onMapReady(GoogleMap googleMap) 
    { 
     mGoogleMap=googleMap; 
     mGoogleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID); 

     //Initialize Google Play Services 
     if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { 
      if (ContextCompat.checkSelfPermission(this, 
        Manifest.permission.ACCESS_FINE_LOCATION) 
        == PackageManager.PERMISSION_GRANTED) { 
       //Location Permission already granted 
       buildGoogleApiClient(); 
       mGoogleMap.setMyLocationEnabled(true); 
      } else { 
       //Request Location Permission 
       checkLocationPermission(); 
      } 
     } 
     else { 
      buildGoogleApiClient(); 
      mGoogleMap.setMyLocationEnabled(true); 
     } 
    } 

    protected synchronized void buildGoogleApiClient() { 
     mGoogleApiClient = new GoogleApiClient.Builder(this) 
       .addConnectionCallbacks(this) 
       .addOnConnectionFailedListener(this) 
       .addApi(LocationServices.API) 
       .build(); 
     mGoogleApiClient.connect(); 
    } 

    @Override 
    public void onConnected(Bundle bundle) { 
     mLocationRequest = new LocationRequest(); 
     mLocationRequest.setInterval(1000); 
     mLocationRequest.setFastestInterval(1000); 
     mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY); 
     if (ContextCompat.checkSelfPermission(this, 
       Manifest.permission.ACCESS_FINE_LOCATION) 
       == PackageManager.PERMISSION_GRANTED) { 
      LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this); 
     } 
    } 

    @Override 
    public void onConnectionSuspended(int i) {} 

    @Override 
    public void onConnectionFailed(ConnectionResult connectionResult) {} 

    @Override 
    public void onLocationChanged(Location location) 
    { 
     mLastLocation = location; 
     if (mCurrLocationMarker != null) { 
      mCurrLocationMarker.remove(); 
     } 


     double latitude = location.getLatitude(); 
     double longitude = location.getLongitude(); 
     double speed = location.getSpeed(); 
     double distance = 0; 
     locations.add(location); 
     for(int i = 0; i < locations.size()-1; i++) { 
      distance += locations.get(i).distanceTo(locations.get(i +1)); 
     } 

     StringBuilder stBuilder = new StringBuilder(); 
     stBuilder.append(" Latitude: "); 
     stBuilder.append(latitude); 
     stBuilder.append("\n"); 
     stBuilder.append(" Logitude: "); 
     stBuilder.append(longitude); 
     stBuilder.append("\n"); 
     stBuilder.append(" Speed: "); 
     stBuilder.append(speed + "       "); 

     stBuilder.append("Distance: "); 
     stBuilder.append(distance); 
     TextView textView = (TextView) findViewById(R.id.textView); 
     textView.setText(stBuilder); 


     //Place current location marker 
     LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 
     MarkerOptions markerOptions = new MarkerOptions(); 
     markerOptions.position(latLng); 
     markerOptions.title("Current Position"); 
     markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)); 
     mCurrLocationMarker = mGoogleMap.addMarker(markerOptions); 

     //move map camera 
     mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,11)); 

     //optionally, stop location updates if only current location is needed 
     if (mGoogleApiClient != null) { 
      LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
     } 
    } 

    public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99; 
    private void checkLocationPermission() { 
     if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) 
       != PackageManager.PERMISSION_GRANTED) { 

      // Should we show an explanation? 
      if (ActivityCompat.shouldShowRequestPermissionRationale(this, 
        Manifest.permission.ACCESS_FINE_LOCATION)) { 

       // Show an explanation to the user *asynchronously* -- don't block 
       // this thread waiting for the user's response! After the user 
       // sees the explanation, try again to request the permission. 
       new AlertDialog.Builder(this) 
         .setTitle("Location Permission Needed") 
         .setMessage("This app needs the Location permission, please accept to use location functionality") 
         .setPositiveButton("OK", new DialogInterface.OnClickListener() { 
          @Override 
          public void onClick(DialogInterface dialogInterface, int i) { 
           //Prompt the user once explanation has been shown 
           ActivityCompat.requestPermissions(MainActivity.this, 
             new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 
             MY_PERMISSIONS_REQUEST_LOCATION); 
          } 
         }) 
         .create() 
         .show(); 


      } else { 
       // No explanation needed, we can request the permission. 
       ActivityCompat.requestPermissions(this, 
         new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 
         MY_PERMISSIONS_REQUEST_LOCATION); 
      } 
     } 
    } 

    @Override 
    public void onRequestPermissionsResult(int requestCode, 
              String permissions[], int[] grantResults) { 
     switch (requestCode) { 
      case MY_PERMISSIONS_REQUEST_LOCATION: { 
       // If request is cancelled, the result arrays are empty. 
       if (grantResults.length > 0 
         && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 

        // permission was granted, yay! Do the 
        // location-related task you need to do. 
        if (ContextCompat.checkSelfPermission(this, 
          Manifest.permission.ACCESS_FINE_LOCATION) 
          == PackageManager.PERMISSION_GRANTED) { 

         if (mGoogleApiClient == null) { 
          buildGoogleApiClient(); 
         } 
         mGoogleMap.setMyLocationEnabled(true); 
        } 

       } else { 

        // permission denied, boo! Disable the 
        // functionality that depends on this permission. 
        Toast.makeText(this, "permission denied", LENGTH_LONG).show(); 
       } 
       return; 
      } 

      // other 'case' lines to check for other 
      // permissions this app might request 
     } 
    } 

} 

Answer 1

ロケーションサービスを停止する必要はありませんと呼ばれる。

さらに、onPause()に追加しています。

@Override 
public void onPause() { 
    super.onPause(); 

    //stop location updates when Activity is no longer active 
    if (mGoogleApiClient != null) { 
     LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
    } 
} 

Answer 2

私は私がやったことはonLocationChanged（）メソッドの中にあった、すべてのものを修正することができましたが、私はマーカーがnullだった場合でないかどうかを確認するためにチェックし、私はそれを削除してからマーカーを更新し、カメラを変更しました残りのコードが動作するようにします。メソッド内にこのコードがすでにありましたが、間違った場所にありました。