我正在尝试实现一种车辆监控系统，其中车辆列表位置显示在地图片段中。我能够显示汽车的运动（通过给定的纬度和经度）。但我想要实现的是类似于优步，其中多辆汽车同时移动，即如果10辆车中的所有10辆汽车应该移动和旋转类似于超级。
$dbh = new PDO('mysql:host=localhost;dbname=mydb', 'username', 'password');
$stmt = $dbh->prepare('
SELECT result.*
FROM result
JOIN student ON result.subject_id = student.code
WHERE student.id = :id
');
$stmt->execute(['id' => $id]);
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);
activitymain.xml
**MoveCar.java**
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ValueAnimator;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.PersistableBundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.animation.LinearInterpolator;
import android.widget.Button;
import android.widget.Toast;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public class MoveCar extends AppCompatActivity {
private GoogleMap googleMap;
SupportMapFragment mapFragment;
Marker marker;
private boolean isMarkerRotating = false;
ArrayList<LatLng> listOfPoints = new ArrayList<>();
int currentPt = 0;
LatLng finalPosition;
Marker mMarker;
Marker mMarker2;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setUpMapIfNeeded();
//new location details
listOfPoints.add(new LatLng(30.701623, 76.684220));
listOfPoints.add(new LatLng(30.702486, 76.685487));
listOfPoints.add(new LatLng(30.703135, 76.684891));
listOfPoints.add(new LatLng(30.703256, 76.685000));
listOfPoints.add(new LatLng(30.703883, 76.685941));
listOfPoints.add(new LatLng(30.703413, 76.685190));
}
private void setUpMapIfNeeded() {
if (mapFragment == null) {
mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
if (mapFragment != null) {
mapFragment.getMapAsync(new OnMapReadyCallback() {
@Override
public void onMapReady(GoogleMap googleMap) {
loadMap(googleMap);
}
});
}
}
}
private void loadMap(GoogleMap map) {
googleMap = map;
mMarker = googleMap.addMarker(new MarkerOptions().position(new LatLng(30.701623, 76.684220)).icon(BitmapDescriptorFactory.fromResource(R.drawable.car_marker)));
// mMarker2 = googleMap.addMarker(new MarkerOptions().position(new LatLng(30.7021811,76.6850622)).icon(BitmapDescriptorFactory.fromResource(R.drawable.car_marker)));
final Handler handler = new Handler();
//Code to move car along static latitude and longitude
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (currentPt < listOfPoints.size()) {
//post again
Log.d("tess", "inside run ");
Location targetLocation = new Location(LocationManager.GPS_PROVIDER);
targetLocation.setLatitude(listOfPoints.get(currentPt).latitude);
targetLocation.setLongitude(listOfPoints.get(currentPt).longitude);
animateMarkerNew(targetLocation, mMarker);
handler.postDelayed(this, 3000);
currentPt++;
} else {
Log.d("tess", "call back removed");
//removed callbacks
handler.removeCallbacks(this);
}
}
}, 3000);
//Here move marker along real time updates
// final RequestParams params = new RequestParams();
// params.put("source_lattitude", "lat");
// params.put("source_longitude", "long");
// params.put("date", "date");
//
// //new handler
// handler.postDelayed(new Runnable() {
// @Override
// public void run() {
//
// LoopjHttpClient.post(getString(R.string.default_upload_website), params, new AsyncHttpResponseHandler() {
// @Override
// public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
//
// try {
// JSONObject jsonObject = new JSONObject(new String(responseBody));
// String status = jsonObject.getString("status");
// String text = jsonObject.getString("text");
// //reading json array
// JSONArray jsonArray = jsonObject.getJSONArray("result");
// String source = jsonArray.getJSONObject(0).getString("source");
//
// String[] latLong = source.split(",");
// Location location = new Location(LocationManager.GPS_PROVIDER);
// location.setLatitude(Double.parseDouble(latLong[0]));
// location.setLongitude(Double.parseDouble(latLong[1]));
// //calling method to animate marker
// animateMarkerNew(location, mMarker);
// } catch (JSONException e) {
// e.printStackTrace();
// }
// }
//
// @Override
// public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
// Log.d("onFailure", "onFailure");
// }
// });
//
// handler.postDelayed(this, 3000);
// }
// }, 3000);
}
private void animateMarkerNew(final Location destination, final Marker marker) {
if (marker != null) {
final LatLng startPosition = marker.getPosition();
final LatLng endPosition = new LatLng(destination.getLatitude(), destination.getLongitude());
final float startRotation = marker.getRotation();
final LatLngInterpolatorNew latLngInterpolator = new LatLngInterpolatorNew.LinearFixed();
ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, 1);
valueAnimator.setDuration(3000); // duration 3 second
valueAnimator.setInterpolator(new LinearInterpolator());
valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
try {
float v = animation.getAnimatedFraction();
LatLng newPosition = latLngInterpolator.interpolate(v, startPosition, endPosition);
marker.setPosition(newPosition);
googleMap.moveCamera(CameraUpdateFactory.newCameraPosition(new CameraPosition.Builder()
.target(newPosition)
.zoom(15.5f)
.build()));
marker.setRotation(getBearing(startPosition, new LatLng(destination.getLatitude(), destination.getLongitude())));
} catch (Exception ex) {
//I don't care atm..
}
}
});
valueAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
// if (mMarker != null) {
// mMarker.remove();
// }
// mMarker = googleMap.addMarker(new MarkerOptions().position(endPosition).icon(BitmapDescriptorFactory.fromResource(R.drawable.icon_car)));
}
});
valueAnimator.start();
}
}
private interface LatLngInterpolatorNew {
LatLng interpolate(float fraction, LatLng a, LatLng b);
class LinearFixed implements LatLngInterpolatorNew {
@Override
public LatLng interpolate(float fraction, LatLng a, LatLng b) {
double lat = (b.latitude - a.latitude) * fraction + a.latitude;
double lngDelta = b.longitude - a.longitude;
// Take the shortest path across the 180th meridian.
if (Math.abs(lngDelta) > 180) {
lngDelta -= Math.signum(lngDelta) * 360;
}
double lng = lngDelta * fraction + a.longitude;
return new LatLng(lat, lng);
}
}
}
//Method for finding bearing between two points
private float getBearing(LatLng begin, LatLng end) {
double lat = Math.abs(begin.latitude - end.latitude);
double lng = Math.abs(begin.longitude - end.longitude);
if (begin.latitude < end.latitude && begin.longitude < end.longitude)
return (float) (Math.toDegrees(Math.atan(lng / lat)));
else if (begin.latitude >= end.latitude && begin.longitude < end.longitude)
return (float) ((90 - Math.toDegrees(Math.atan(lng / lat))) + 90);
else if (begin.latitude >= end.latitude && begin.longitude >= end.longitude)
return (float) (Math.toDegrees(Math.atan(lng / lat)) + 180);
else if (begin.latitude < end.latitude && begin.longitude >= end.longitude)
return (float) ((90 - Math.toDegrees(Math.atan(lng / lat))) + 270);
return -1;
}
}
到目前为止，我能够使用静态数据移动一辆汽车。我想动态地为许多汽车做同样的事情。任何帮助将不胜感激。
提前致谢