android - 如何使用 android studio 制作一个简单的跟踪 android 应用程序

Question

我正在尝试制作一个简单的位置跟踪应用程序我尝试了很多方法但没有任何效果。我认为没有调用 onLocationChanged。

这是我的代码:

@Override
public void onLocationChanged(Location location) {
    Log.d("test", "onLocationChanged Called");
    double latitude = location.getLatitude();
    double longitude = location.getLongitude();
    LatLng latLng = new LatLng(latitude, longitude);
    gMap.addMarker(new MarkerOptions().position(latLng));
    gMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
    gMap.animateCamera(CameraUpdateFactory.zoomTo(15));
    Log.d("location", "Latitude:" + latitude + ", Longitude:" + longitude);
}

Answer 1

这是我运行应用程序的完整代码。只需创建新项目并选择 map 项目，在谷歌控制台上创建您的项目并将 key 添加到您的项目:

添加权限 list :

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

Java 代码:

package com.bluebirds.avinash.uberdemo;

import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Point;
import android.location.Location;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import android.widget.Button;
import android.widget.TextView;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.PendingResult;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
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.Projection;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

public class MapsActivity extends FragmentActivity implements LocationListener,
        OnMapReadyCallback, GoogleApiClient
                .ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {

    private GoogleMap mMap;
    private final int MY_LOCATION_REQUEST_CODE = 100;
    private Handler handler;
    private Marker m;
//    private GoogleApiClient googleApiClient;

    public final static int SENDING = 1;
    public final static int CONNECTING = 2;
    public final static int ERROR = 3;
    public final static int SENT = 4;
    public final static int SHUTDOWN = 5;

    private static final String TAG = "LocationActivity";
    private static final long INTERVAL = 1000 * 10;
    private static final long FASTEST_INTERVAL = 1000 * 5;
    Button btnFusedLocation;
    TextView tvLocation;
    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;
    Location mCurrentLocation;
    String mLastUpdateTime;
    private Location previousLocation;

    protected void createLocationRequest() {
        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(INTERVAL);
        mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    }

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

        createLocationRequest();
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .build();

        // 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);

        handler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                switch (msg.what) {

                    case SENDING:

                        break;

                }

            }
        };
    }


    /**
     * Manipulates the map once available.
     * This callback is triggered when the map is ready to be used.
     * This is where we can add markers or lines, add listeners or move the camera. In this case,
     * we just add a marker near Sydney, Australia.
     * If Google Play services is not installed on the device, the user will be prompted to install
     * it inside the SupportMapFragment. This method will only be triggered once the user has
     * installed Google Play services and returned to the app.
     */
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        // Add a marker in Sydney and move the camera
        LatLng sydney = new LatLng(-34, 151);

        m = mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in " +
                "Sydney"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));


        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            mMap.setMyLocationEnabled(true);
        } else {
            // Show rationale and request permission.
        }


    }


    public void rotateMarker(final Marker marker, final float toRotation, final float st) {
        final Handler handler = new Handler();
        final long start = SystemClock.uptimeMillis();
        final float startRotation = st;
        final long duration = 1555;

        final Interpolator interpolator = new LinearInterpolator();

        handler.post(new Runnable() {
            @Override
            public void run() {
                long elapsed = SystemClock.uptimeMillis() - start;
                float t = interpolator.getInterpolation((float) elapsed / duration);

                float rot = t * toRotation + (1 - t) * startRotation;

                marker.setRotation(-rot > 180 ? rot / 2 : rot);
                if (t < 1.0) {
                    // Post again 16ms later.
                    handler.postDelayed(this, 16);
                }
            }
        });
    }


    public void animateMarker(final LatLng toPosition, final boolean hideMarke) {
        final Handler handler = new Handler();
        final long start = SystemClock.uptimeMillis();
        Projection proj = mMap.getProjection();
        Point startPoint = proj.toScreenLocation(m.getPosition());
        final LatLng startLatLng = proj.fromScreenLocation(startPoint);
        final long duration = 5000;

        final Interpolator interpolator = new LinearInterpolator();

        handler.post(new Runnable() {
            @Override
            public void run() {
                long elapsed = SystemClock.uptimeMillis() - start;
                float t = interpolator.getInterpolation((float) elapsed
                        / duration);
                double lng = t * toPosition.longitude + (1 - t)
                        * startLatLng.longitude;
                double lat = t * toPosition.latitude + (1 - t)
                        * startLatLng.latitude;
                m.setPosition(new LatLng(lat, lng));

                if (t < 1.0) {
                    // Post again 16ms later.
                    handler.postDelayed(this, 16);
                } else {
                    if (hideMarke) {
                        m.setVisible(false);
                    } else {
                        m.setVisible(true);
                    }
                }
            }
        });
    }

    private double bearingBetweenLocations(LatLng latLng1, LatLng latLng2) {

        double PI = 3.14159;
        double lat1 = latLng1.latitude * PI / 180;
        double long1 = latLng1.longitude * PI / 180;
        double lat2 = latLng2.latitude * PI / 180;
        double long2 = latLng2.longitude * PI / 180;

        double dLon = (long2 - long1);

        double y = Math.sin(dLon) * Math.cos(lat2);
        double x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1)
                * Math.cos(lat2) * Math.cos(dLon);

        double brng = Math.atan2(y, x);

        brng = Math.toDegrees(brng);
        brng = (brng + 360) % 360;

        return brng;
    }


   /* @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[]
            grantResults) {
        if (requestCode == MY_LOCATION_REQUEST_CODE) {
            if (permissions.length == 1 &&
                    permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION &&
                    grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                mMap.setMyLocationEnabled(true);
            } else {
                // Permission was denied. Display an error message.
            }
        }
    }*/

    @Override
    public void onConnected(@Nullable Bundle bundle) {

        Log.d(TAG, "onConnected - isConnected ...............: " + mGoogleApiClient.isConnected());
        startLocationUpdates();
    }

    @Override
    protected void onStart() {
        super.onStart();
        Log.d(TAG, "onStart fired ..............");
        mGoogleApiClient.connect();
    }

    @Override
    protected void onStop() {
        super.onStop();

        mGoogleApiClient.disconnect();
        Log.d(TAG, "isConnected ...............: " + mGoogleApiClient.isConnected());
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

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

    }

    protected void startLocationUpdates() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) !=
                PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        PendingResult<Status> pendingResult = LocationServices.FusedLocationApi
                .requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
        Log.d(TAG, "Location update started ..............: ");
    }

    LatLng previouslatLng;

    @Override
    public void onLocationChanged(Location location) {
        previouslatLng = new LatLng(location.getLatitude(), location.getLongitude());

        double rota = 0.0;
        double startrota = 0.0;
        if (previousLocation != null) {

            rota = bearingBetweenLocations(previouslatLng, new LatLng(location.getLatitude
                    (), location.getLongitude()));
        }


        rotateMarker(m, (float) rota, (float) startrota);


        previousLocation = location;
        Log.d(TAG, "Firing onLocationChanged..........................");
        Log.d(TAG, "lat :" + location.getLatitude() + "long :" + location.getLongitude());
        Log.d(TAG, "bearing :" + location.getBearing());

        animateMarker(new LatLng(location.getLatitude(), location.getLongitude()), false);
//        new ServerConnAsync(handler, MapsActivity.this,location).execute();


    }

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

    protected void stopLocationUpdates() {
        LocationServices.FusedLocationApi.removeLocationUpdates(
                mGoogleApiClient, this);
        Log.d(TAG, "Location update stopped .......................");
    }

    @Override
    public void onResume() {
        super.onResume();
        if (mGoogleApiClient.isConnected()) {
            startLocationUpdates();
            Log.d(TAG, "Location update resumed .....................");
        }
    }
}

XML Activity :

<fragment android:id="@+id/map"
          android:name="com.google.android.gms.maps.SupportMapFragment"
          xmlns:android="http://schemas.android.com/apk/res/android"
          xmlns:map="http://schemas.android.com/apk/res-auto"
          xmlns:tools="http://schemas.android.com/tools"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          tools:context="com.bluebirds.avinash.uberdemo.MapsActivity"/>