Android：マーカーを中央に維持しながら地図をドラッグ

Question

現在、MapActivityで現在の位置（緯度、経度）を取得しています。今私は、マーカーを中央に維持しながら、ユーザーが地図を移動させたいと思っています。これは、地図が移動されるたびに現在の場所が更新されることを意味します。 （右？）

私はこれに続いてandroid How to move a map under a markerとHow to attach a flexible marker on map something like Uber and Lyft?しかし、私の概念を明確にすることができませんでした。

Activity_map.xml（ここで私が追加したImageViewの）あなたのヘルプははるかに高く評価されます

public class MapActivity extends FragmentActivity implements  OnMapReadyCallback, 
    GoogleApiClient.ConnectionCallbacks, 
    GoogleApiClient.OnConnectionFailedListener, 
    LocationListener,GoogleMap.OnInfoWindowClickListener{ 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_map); 
    // int x =_st.jsonArray.length(); 
    if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { 
     checkLocationPermission(); 
    } 

    // Obtain the SupportMapFragment and get notified when the map is ready to be used. 
    SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager() 
      .findFragmentById(R.id.map); 
    mapFragment.getMapAsync(this); 

    fragmentOnMap = (FragmentOnMap)getFragmentManager().findFragmentById(R.id.fragment_bottom); 
    getFragmentManager().beginTransaction().hide(fragmentOnMap); 

} 

@Override 
public void onMapReady(GoogleMap googleMap) { 


    //Get Last Known Location and convert into Current Longitute and Latitude 
    final LocationManager mlocManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); 
    final Location currentGeoLocation = mlocManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 

    double currentLat = currentGeoLocation.getLatitude(); 
    double currentLon = currentGeoLocation.getLongitude(); 

    LatLng currentLatLng = new LatLng(currentLat,currentLon); 
    //Toast.makeText(this,"Cur Lat" +currentLat+"Lon"+currentLon,Toast.LENGTH_LONG).show(); 

    // Get JSON String and Break it down into individual nodes 
    //double x=_location.getLatitude(); 
    //double y=_location.getLongitude(); 
    json_string = getIntent().getExtras().getString("JSON_DTA"); 
    LatLng latLng = null; 
    try { 
     int count = 0; 
     //jsonObject = new JSONObject(json_string); 
     jsonArray = new JSONArray(json_string); 

     while (count < jsonArray.length()) { 
      JSONObject JO = jsonArray.getJSONObject(count); 
      _id = JO.getInt("id"); 
      _doctorname = JO.getString("doctorname"); 
      _doclat = JO.getString("latitude"); 
      _doclong = JO.getString("longitude"); 

      count++; 

      Double d = Double.parseDouble(_doclat); 
      Double e = Double.parseDouble(_doclong); 
      latLng = new LatLng(d, e); 

      DecimalFormat df = new DecimalFormat("####0.0"); 

      DistanceBetweenPoints distanceBetweenPoints = new DistanceBetweenPoints(); 
      double distance = distanceBetweenPoints.CalculationByDistance(currentLatLng,latLng); 

      double distanceThreshHold = 7 ; 
      if(distance < distanceThreshHold ) 
      { 
       mMap = googleMap; 
       mMap.setOnInfoWindowClickListener(this); 
       MarkerOptions _markeroptions = new MarkerOptions() 
         .position(latLng) 
         .title(_doctorname+": " + df.format(distance) + " KM") 
         .icon(BitmapDescriptorFactory.fromResource(R.drawable.smallest_logo)); 
       mMap.addMarker(_markeroptions); 

       mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL); 


      } 
      else 
      { 
       mMap = googleMap; 
      } 

    } 


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

    //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) { 
      buildGoogleApiClient(); 

      mMap.setMyLocationEnabled(true); 

     } 
    } else { 
     buildGoogleApiClient(); 
     mMap.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(@Nullable 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 onLocationChanged(Location location) { 

     mLastLocation = location; 
     if (mCurrLocationMarker != null) { 
      mCurrLocationMarker.remove(); 
     } 


     //Place current location marker 
     LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 
     MarkerOptions markerOptions = new MarkerOptions(); 
     markerOptions.position(latLng); 
     markerOptions.title("Current Position"); 
     markerOptions.draggable(true); 

     markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)); 
     mCurrLocationMarker = mMap.addMarker(markerOptions); 


     // Toast.makeText(this, "Current" + latLng, Toast.LENGTH_LONG).show(); 
     String tag = null; 
     Log.d(tag, "lon: " + location.getLongitude() + " ----- lat: " + location.getLatitude()); 


     //move map camera 
     mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng)); 
     mMap.animateCamera(CameraUpdateFactory.zoomTo(11)); 


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


    } 




@Override 
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) { 

} 

public boolean checkLocationPermission(){ 
    if (ContextCompat.checkSelfPermission(this, 
      Manifest.permission.ACCESS_FINE_LOCATION) 
      != PackageManager.PERMISSION_GRANTED) { 

     // Asking user if explanation is needed 
     if (ActivityCompat.shouldShowRequestPermissionRationale(this, 
       Manifest.permission.ACCESS_FINE_LOCATION)) { 

      // Show an expanation 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. 

      //Prompt the user once explanation has been shown 
      ActivityCompat.requestPermissions(this, 
        new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 
        MY_PERMISSIONS_REQUEST_LOCATION); 


     } else { 
      // No explanation needed, we can request the permission. 
      ActivityCompat.requestPermissions(this, 
        new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 
        MY_PERMISSIONS_REQUEST_LOCATION); 
     } 
     return false; 
    } else { 
     return true; 
    } 
} 
@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. 
       if (ContextCompat.checkSelfPermission(this, 
         Manifest.permission.ACCESS_FINE_LOCATION) 
         == PackageManager.PERMISSION_GRANTED) { 

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

      } else { 

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

     // other 'case' lines to check for other permissions this app might request. 
     //You can add here other case statements according to your requirement. 
    } 
} 

次のように

<RelativeLayout 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
xmlns:android="http://schemas.android.com/apk/res/android"> 

<fragment 
    android:id="@+id/map" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    class="com.google.android.gms.maps.MapFragment" 
    /> 

<ImageView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_centerInParent="true" 
    android:src="@drawable/gps" 
    /> 

</RelativeLayout> 

マイMapActivityです。ありがとうございました。

Answer 1

あなたのマーカーアイコンを使ってImageViewの下にマップを置くのが最良の方法です（地図の断片を下にして枠線を描き、上に中央のマーカ画像が機能するはずです）。次に、マップの移動が終了したときにコールバックを受け取るOnCameraIdleListenerを使用できます。だからそのような動きのコールバックを待機するために、あなたのマップにOnCameraIdleListenerのインスタンスを設定します。

map.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() { 
     @Override 
     public void onCameraIdle() { 
      //get latlng at the center by calling 
      LatLng midLatLng = map.getCameraPosition().target; 
     } 
    }); 

Answer 2

は、最初にあなたのActivity_map.xmlため、このレイアウトを試してみてください：

<RelativeLayout 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

    <fragment 
     android:id="@+id/map" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     class="com.google.android.gms.maps.MapFragment" 
    /> 

    <ImageView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_centerInParent="true" 
     android:src="@drawable/gps" 
    /> 

</RelativeLayout>