Question

我正在尝试添加折线连接谷歌地图中的一组点。当我构建应用程序时，我没有得到任何错误但是没有出现折线。如果我调用isvisible（）方法它返回true.Please Help

@Override
public void onMapReady(GoogleMap googleMap) {
   // new LongOperation().execute("");

   /* googleMap.setMapStyle(
            MapStyleOptions.loadRawResourceStyle(
                    this, R.raw.mapjson));*/

    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;
    }
    googleMap.setMyLocationEnabled(true);
    googleMapnew = googleMap;
    Polyline polyline1 = googleMap.addPolyline(new PolylineOptions()
            .clickable(true)
            .add(
                    new LatLng(13.034063, 77.567006 ),
                    new LatLng(13.034087, 77.568629),
                    new LatLng(13.034202, 77.569431),
                    new LatLng(13.034371, 77.570103),
                    new LatLng(13.034535, 77.570121),
                    new LatLng(13.036526, 77.570489),
                    new LatLng(13.037719, 77.570545),
                    new LatLng(13.038252, 77.570039),
                    new LatLng(13.039849, 77.570028),
                    new LatLng(13.040153, 77.569229),
                    new LatLng(13.040640, 77.568512),
                    new LatLng(13.041071, 77.567996),
                    new LatLng(13.041780, 77.567894))
    .color(Color.GREEN)
    .width(66));
    Log.e("polylog", String.valueOf(polyline1.isVisible()));
    Log.e("polylog", String.valueOf(polyline1));

}

Answer 1

问题出在

googleMap.setMyLocationEnabled(true);

行，因为您可能没有向您的应用授予ACCESS_FINE_LOCATION和ACCESS_COARSE_LOCATION。您应该通过Android设备的Applications菜单手动将其授予您的应用，或者实现Official Documentation中的检查和授予权限，例如this的Daniel Nugent回复，类似的东西：

public class MainActivity extends AppCompatActivity implements OnMapReadyCallback {

    private static final int LOCATION_PERMISSION_REQUEST_CODE = 101;
    private GoogleMap mGoogleMap;
    private MapFragment mMapFragment;

    private void makeLocationPermissionRequest() {
        ActivityCompat.requestPermissions(this,
                new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_PERMISSION_REQUEST_CODE);
    }

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

        mMapFragment = (MapFragment) getFragmentManager()
                .findFragmentById(R.id.map_fragment);
        mMapFragment.getMapAsync(this);
    }

    private void showPolyline() {

        mGoogleMap.setMyLocationEnabled(true);

        Polyline polyline1 = mGoogleMap.addPolyline(new PolylineOptions()
                .clickable(true)
                .add(
                        new LatLng(13.034063, 77.567006 ),
                        new LatLng(13.034087, 77.568629),
                        new LatLng(13.034202, 77.569431),
                        new LatLng(13.034371, 77.570103),
                        new LatLng(13.034535, 77.570121),
                        new LatLng(13.036526, 77.570489),
                        new LatLng(13.037719, 77.570545),
                        new LatLng(13.038252, 77.570039),
                        new LatLng(13.039849, 77.570028),
                        new LatLng(13.040153, 77.569229),
                        new LatLng(13.040640, 77.568512),
                        new LatLng(13.041071, 77.567996),
                        new LatLng(13.041780, 77.567894))
                .color(Color.GREEN)
                .width(66));

        mGoogleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(13.034063, 77.567006), 12));
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mGoogleMap = googleMap;

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            int locationPermission = ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION);
            if (locationPermission != PackageManager.PERMISSION_GRANTED) {
                makeLocationPermissionRequest();
            } else {
                showPolyline();
            }
        } else {
            showPolyline();
        }
}

    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case LOCATION_PERMISSION_REQUEST_CODE: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    showPolyline();
                } else {
                }
                return;
            }
        }
    }

}

别忘了添加

到您的AndroidManifest.xml文件。你有类似的东西：

折线在谷歌地图中不可见

1 个答案: