java - 使用多个位置地理围栏

Question

我用过这段代码

( https://www.youtube.com/watch?v=nmAtMqljH9M&list=PLdHg5T0SNpN3GBUmpGqjiKGMcBaRT2A-m&index=9&ab_channel=yoursTRULY )

( https://github.com/trulymittal/Geofencing )

该代码通过点击创建地理围栏并且只使用一个地理围栏。

但我想在地理围栏启动时多一个固定标记，并使用多一个地理围栏。

所以我修改了这段代码(MapsActivity.java)

package com.example.geofencing;

import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.FragmentActivity;

import android.Manifest;
import android.app.PendingIntent;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

import com.google.android.gms.location.Geofence;
import com.google.android.gms.location.GeofencingClient;
import com.google.android.gms.location.GeofencingRequest;
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.SupportMapFragment;
import com.google.android.gms.maps.model.CircleOptions;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;

import java.util.ArrayList;
import java.util.List;

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private static final String TAG = "MapsActivity";

    private GoogleMap mMap;
    private GeofencingClient geofencingClient;
    private GeofenceHelper geofenceHelper;

    private float GEOFENCE_RADIUS = 20;
    private String GEOFENCE_ID = "SOME_GEOFENCE_ID";

    private int FINE_LOCATION_ACCESS_REQUEST_CODE = 10001;
    private int BACKGROUND_LOCATION_ACCESS_REQUEST_CODE = 10002;

    private List<LatLng> latLng;

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

        geofencingClient = LocationServices.getGeofencingClient(this);
        geofenceHelper = new GeofenceHelper(this);
    }


    /**
     * 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;
       
        //move the camera to the starting point
        LatLng latLng_start = new LatLng(37.462749, 126.910311);
        mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng_start, 16));

        latLng = new ArrayList<>();
        latLng.add(new LatLng(38.462349, 123.909955));
        latLng.add(new LatLng(38.463194, 123.911317));
        latLng.add(new LatLng(38.462720, 123.910768));
        latLng.add(new LatLng(38.462743, 123.910317));

        for (LatLng i : latLng) {
            addMarker(i);
            addCircle(i, GEOFENCE_RADIUS);
            addGeofence(i, GEOFENCE_RADIUS);
        }


//        for (int i = 0; i < markerLocation.length; i++) {
//            LatLng latLng = new LatLng(markerLocation[i][0], markerLocation[i][1]);
//            addMarker(latLng);
//            addCircle(latLng, GEOFENCE_RADIUS);
//            addGeofence(latLng, GEOFENCE_RADIUS);
//        }
        enableUserLocation();
    }

    private void enableUserLocation() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
            mMap.setMyLocationEnabled(true);
        } else {
            //Ask for permission
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION)) {
                //We need to show user a dialog for displaying why the permission is needed and then ask for the permission...
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, FINE_LOCATION_ACCESS_REQUEST_CODE);
            } else {
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, FINE_LOCATION_ACCESS_REQUEST_CODE);
            }
        }
    }

    private void addMarker(LatLng latLng) {
        MarkerOptions markerOptions = new MarkerOptions().position(latLng);
        mMap.addMarker(markerOptions);
    }

    private void addCircle(LatLng latLng, float radius) {
        CircleOptions circleOptions = new CircleOptions();
        circleOptions.center(latLng);
        circleOptions.radius(radius);
        circleOptions.strokeColor(Color.argb(255, 255, 0, 0));
        circleOptions.fillColor(Color.argb(64, 255, 0, 0));
        circleOptions.strokeWidth(4);
        mMap.addCircle(circleOptions);
    }

    private void addGeofence(LatLng latLng, float radius) {

        Geofence geofence = geofenceHelper.getGeofence(GEOFENCE_ID, latLng, radius, Geofence.GEOFENCE_TRANSITION_ENTER | Geofence.GEOFENCE_TRANSITION_DWELL | Geofence.GEOFENCE_TRANSITION_EXIT);
        GeofencingRequest geofencingRequest = geofenceHelper.getGeofencingRequest(geofence);
        PendingIntent pendingIntent = geofenceHelper.getPendingIntent();

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_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;
        }
        geofencingClient.addGeofences(geofencingRequest, pendingIntent)
                .addOnSuccessListener(new OnSuccessListener<Void>() {
                    @Override
                    public void onSuccess(Void aVoid) {
                        Log.d(TAG, "onSuccess: Geofence Added...");
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {
                        String errorMessage = geofenceHelper.getErrorString(e);
                        Log.d(TAG, "onFailure: " + errorMessage);
                    }
                });
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == FINE_LOCATION_ACCESS_REQUEST_CODE) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //We have the permission
                mMap.setMyLocationEnabled(true);
            } else {
                //We do not have the permission..

            }
        }

        if (requestCode == BACKGROUND_LOCATION_ACCESS_REQUEST_CODE) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //We have the permission
                Toast.makeText(this, "You can add geofences...", Toast.LENGTH_SHORT).show();
            } else {
                //We do not have the permission..
                Toast.makeText(this, "Background location access is neccessary for geofences to trigger...", Toast.LENGTH_SHORT).show();
            }
        }
    }
}

因此，当启动应用程序时， map 上添加了四个标记和圆圈(我添加了 fout latLng)!

但只有最后一个 latLng 可以使用地理围栏功能(LatLng(38.462743, 123.910317)，比如进入地方报警)，

其他的没有地理围栏功能。

我想让其他位置很好地使用地理围栏功能，哈哈

请。帮帮我:(

我需要一个提示

Answer 1

您正在为每个 LatLng 坐标创建一个新的地理围栏请求。相反，您应该创建一个地理围栏请求，其中包含您要监控的所有地理围栏的列表:

创建一个函数来构建您的地理围栏请求:

private GeofencingRequest getGeofencingRequest() {
    ArrayList<Geofence> geofenceList = new ArrayList<>();
    
    // Iterate through your LatLng(s) to build the Geofence list
    for(LatLng coordinate: latLngList){

        // Set up each Geofence with your corresponding values
        geofenceList.add(new Geofence.Builder()
                .setRequestId("My Geofence ID") // A string to identify this geofence
                .setCircularRegion(coordinate.latitude, coordinate.longitude, Constants.GEOFENCE_LARGE_RADIUS_IN_METERS)
                .setExpirationDuration(Constants.GEOFENCE_EXPIRATION_IN_MILLISECONDS)
                .setTransitionTypes(Geofence.GEOFENCE_TRANSITION_ENTER)
                .build()
        );
    }
    
    GeofencingRequest.Builder builder = new GeofencingRequest.Builder();

    // The INITIAL_TRIGGER_ENTER flag indicates that geofencing service should trigger a
    // GEOFENCE_TRANSITION_ENTER notification when the geofence is added and if the device
    // is already inside that geofence.
    builder.setInitialTrigger(GeofencingRequest.INITIAL_TRIGGER_ENTER);

    // Add the geofences to be monitored by geofencing service using the list we created.
    builder.addGeofences(geofenceList);

    return builder.build();
}

您应该将 addGeofence() 更改为如下所示:

private void addGeofences() {
    PendingIntent pendingIntent = geofenceHelper.getPendingIntent();

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_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;
    }
    
    // Pass the request built with the getGeofencingRequest() function to the Geofencing Client
    geofencingClient.addGeofences(getGeofencingRequest(), pendingIntent)
            .addOnSuccessListener(new OnSuccessListener<Void>() {
                @Override
                public void onSuccess(Void aVoid) {
                    Log.d(TAG, "onSuccess: Geofence Added...");
                }
            })
            .addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception e) {
                    String errorMessage = geofenceHelper.getErrorString(e);
                    Log.d(TAG, "onFailure: " + errorMessage);
                }
            });
}

最后，在你的 onMapReady() 中:

latLngList = new ArrayList<>();
latLngList.add(new LatLng(38.462349, 123.909955));
latLngList.add(new LatLng(38.463194, 123.911317));
latLngList.add(new LatLng(38.462720, 123.910768));
latLngList.add(new LatLng(38.462743, 123.910317));

addGeofences(); // Add all of your geofences to the client