Question

我的目标是在一个单独的课程中完成以下任务。

我想在Google Android Map API中指出两个指针（导航抽屉中的当前位置和前缀位置）之间的方向。

是否可以使用Directions API？无法在Android Maps API中进行指导吗？
我的目标是只为所有任务使用一个活动或java文件，例如获取当前位置并在地图中显示目标指针（我已经完成）。现在我想给这两个指针指定路由，当使用前缀指针或位置改变时，路径必须改变。

前缀是指我在onNavigationItemSelected（）中if else中已经给出的位置。

请参考以下代码，即MainActivity.java - 我的目标是完成一个java类本身的所有任务。

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

private GoogleMap mMap;
private GoogleApiClient client;

Location location;
LocationManager locationManager;

Marker marker;

String title;
String subTitle;
LatLng latLon;

double latitude;
double longitude;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_main);

    isConnectionAvailable();
    isGpsAvailable();

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);

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

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();

}

private boolean isConnectionAvailable() {

    boolean netCon = false;

    try {

        //Internet & network information "Object" initialization
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
        //Internet enable & connectivity checking
        if ("WIFI".equals(networkInfo.getTypeName()) || "MOBILE".equals(networkInfo.getTypeName()) && networkInfo != null && networkInfo.isAvailable() && networkInfo.isConnectedOrConnecting()) {
            netCon = true;
        }
    } catch (Exception e) {
        new AlertDialog.Builder(this)
                .setIcon(android.R.drawable.ic_dialog_alert)
                .setTitle("No Network Connection!")
                .setMessage("Please connect your device to either WiFi or switch on Mobile Data, operator charges may apply!")
                .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                        finish();
                    }
                }).show();
    }
    return netCon;
}

private boolean isGpsAvailable() {

    boolean gpsCon = false;

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
        Toast.makeText(this, "GPS is Enabled.", Toast.LENGTH_SHORT).show();
        gpsCon = true;
    } else {
        new AlertDialog.Builder(this)
                .setIcon(android.R.drawable.ic_dialog_alert)
                .setTitle("GPS is disabled!")
                .setMessage("Without GPS this application will not work! Would you like to enable the GPS?")
                .setCancelable(false)
                .setPositiveButton("Enable GPS", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        Intent callGpsSetting = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                        startActivity(callGpsSetting);
                    }
                })
                .setNegativeButton("Exit.", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                        finish();
                    }
                })
                .show();
    }
    return gpsCon;
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        client.disconnect();
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.redBuilding){
        latitude = 13.0827;
        longitude = 80.2707;

        title = "Chennai";
        subTitle = "TN";

        latLon = new LatLng(latitude, longitude);
    }
    mMap.clear();
    mMap.addMarker(new MarkerOptions().position(latLon).title(title).snippet(subTitle)).showInfoWindow();
    CameraPosition cameraPosition = new CameraPosition.Builder().target(latLon).tilt(30).zoom(20).build();
    mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));

    if (id == R.id.nav_share) {
    } else if (id == R.id.nav_send) {
    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
    mMap.setMyLocationEnabled(true);
    buildGoogleApiClient();
}

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

public Action getIndexApiAction() {
    Thing object = new Thing.Builder()
            .setName("CEG") // TODO: Define a title for the content shown.
            // TODO: Make sure this auto-generated URL is correct.
            .setUrl(Uri.parse("http://[ENTER-YOUR-URL-HERE]"))
            .build();
    return new Action.Builder(Action.TYPE_VIEW)
            .setObject(object)
            .setActionStatus(Action.STATUS_TYPE_COMPLETED)
            .build();
}

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

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    client.connect();
    AppIndex.AppIndexApi.start(client, getIndexApiAction());
}

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

    // ATTENTION: This was auto-generated to implement the App Indexing API.
    // See https://g.co/AppIndexing/AndroidStudio for more information.
    if (client.isConnected()) {
        AppIndex.AppIndexApi.end(client, getIndexApiAction());
        client.disconnect();
    }
}

@Override
public void onConnected(Bundle bundle) {
    location = LocationServices.FusedLocationApi.getLastLocation(client);
    if (location != null) {
        latitude = location.getLatitude();
        longitude = location.getLongitude();
    }
    LatLng latLon = new LatLng(latitude, longitude);
    mMap.addMarker(new MarkerOptions().position(latLon)
            .title("You are here.").snippet("Choose destination from menu to navigate.")
            .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA))
    ).showInfoWindow();
    CameraPosition cameraPosition = new CameraPosition.Builder().target(latLon).tilt(30).zoom(20).build();
    mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}

@Override
public void onConnectionSuspended(int i) {

}

@Override
public void onLocationChanged(Location location) {

    location = location;

    //Place current location marker
    LatLng latLon = new LatLng(location.getLatitude(), location.getLongitude());
    mMap.clear();
    mMap.addMarker(new MarkerOptions().position(latLon)
            .title("You are here.").snippet("Choose destination from menu to navigate.")
            .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA))
    ).showInfoWindow();
    CameraPosition cameraPosition = new CameraPosition.Builder().target(latLon).tilt(30).zoom(20).build();
    mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));

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

}

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

}

public static final int MY_PERMISSIONS_REQUEST_LOCATION = 0;

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 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.

            //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. Do the
                // contacts-related task you need to do.
                if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                    if (client == 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.
    }
}
}

我想从我的类似问题迭代原因，尽管可用的解决方案是 - 我的目标是只使用一个java类，有使用多个java类和文件的解决方案。

Answer 1

你需要方向api。这是一个很好的教程：

https://www.androidtutorialpoint.com/intermediate/google-maps-draw-path-two-points-using-google-directions-google-map-android-api-v2/

您可以将所有代码放在一个类中。但最好使用多个类。

Answer 2

如果您已经在使用Google Maps Fragment，并且只想在地图上添加线（即记录一条路线与绘制一条路线），那么添加一条线（称为折线）就很简单了。

首先创建一个PolyLineOptions（保存引用可以让您以后对其进行更新）：

PolylineOptions routeLine;
LatLng pos = new LatLng(location.getLatitude(), location.getLongitude());
routeLine = new PolylineOptions().add(pos);

这时将不会显示该线，要使其显示出来，有两个要求：将其添加到地图中并再添加至少一个点：

routeLine.add(new LatLng(nextLocation.getLatitude(), nextLocation.getLongitude()));
map.addPolyline(routeLine);

如何使用Google Maps Android API在MapFragment中的两点之间绘制路线

2 个答案: