将当前位置添加到 fragment.class

Question

我有点困惑...在互联网上找不到任何东西。

我想在选项卡片段中显示 google 地图。它运作良好。但是如何将当前的经度和纬度设置为片段呢？

这里是 xml:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".TabMap"
android:background="#DBDBDB">

<com.google.android.gms.maps.MapView
    android:id="@+id/map"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginBottom="60dp"
    android:layout_marginLeft="20dp"
    android:layout_marginRight="20dp"
    android:layout_marginTop="10dp">

</com.google.android.gms.maps.MapView>

地图片段

public class TabMap extends Fragment implements OnMapReadyCallback{

GoogleMap mGoogleMap ;
MapView mMapView;
View mView;

Location location = new Location();

public TabMap() {
    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    mView =  inflater.inflate(R.layout.fragment_tab_map, container, false);
    return mView;
}


@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    mMapView = (MapView) mView.findViewById(R.id.map);
    if(mMapView != null) {
        mMapView.onCreate(null);
        mMapView.onResume();
        mMapView.getMapAsync(this);
    }
}

@Override
public void onMapReady(GoogleMap googleMap) {

    MapsInitializer.initialize(getContext());

    mGoogleMap = googleMap;
    googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

    googleMap.addMarker(new MarkerOptions().position(new LatLng(51.1657, 10.4515)).title("Germany"));

    CameraPosition de = CameraPosition.builder().target(new LatLng(51.1657, 10.4515)).zoom(6).bearing(0).build();

    googleMap.moveCamera(CameraUpdateFactory.newCameraPosition(de));
}

}

location.class

public class Location extends AppCompatActivity {

private static final int REQUEST_CODE = 1000;
TextView txtLocation;
Button btnLocation, btnStop;

AutoCompleteTextView gMap;

FusedLocationProviderClient fusedLocationProviderClient;
LocationRequest locationRequest;
LocationCallback locationCallback;

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);

    switch (requestCode) {
        case REQUEST_CODE: {
            if (grantResults.length > 0) {
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                } else if (grantResults[0] == PackageManager.PERMISSION_DENIED) {

                }
            }
        }
    }
}

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

    Button button = (Button) findViewById(R.id.button3);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(v.getContext(), MainActivity.class);
            startActivityForResult(intent, 0);
        }
    });

    txtLocation = (TextView) findViewById(R.id.txtLocation);
    btnLocation = (Button) findViewById(R.id.btnLocation);
    btnStop = (Button) findViewById(R.id.btnStop);

    if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION))
    {

        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_CODE);
    } else {
        buildLocationRequest();
        buildLocationCallBack();

        fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);

        btnLocation.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (ActivityCompat.checkSelfPermission(Location.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
                        && ActivityCompat.checkSelfPermission(Location.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(Location.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_CODE);
                    return;
                }
                fusedLocationProviderClient.requestLocationUpdates(locationRequest, locationCallback, Looper.myLooper());

                btnLocation.setEnabled(!btnLocation.isEnabled());
                btnStop.setEnabled(!btnStop.isEnabled());
            }
        });

        btnStop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (ActivityCompat.checkSelfPermission(Location.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
                        && ActivityCompat.checkSelfPermission(Location.this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(Location.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_CODE);
                    return;
                }
                fusedLocationProviderClient.removeLocationUpdates(locationCallback);

                btnLocation.setEnabled(!btnLocation.isEnabled());
                btnStop.setEnabled(!btnStop.isEnabled());
            }
        });

    }
}

public void buildLocationCallBack() {
    locationCallback = new LocationCallback(){
        @Override
        public void onLocationResult(LocationResult locationResult) {
            for(android.location.Location location:locationResult.getLocations())
                txtLocation.setText(String.valueOf(location.getLatitude())
                        + "/" +
                        String.valueOf(location.getLongitude()));
        }
    };
}

private void buildLocationRequest() {
    locationRequest = new LocationRequest();
    locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    locationRequest.setInterval(5000);
    locationRequest.setFastestInterval(3000);
    locationRequest.setSmallestDisplacement(10);

}

}

所以。我有一个带有添加位置选项的导航栏（location.class）它打开并点击 "current location" 按钮，它在 TextView 中显示纬度和经度。

但是我如何将这些信息提供给TabMap.class、googleMap.addMarker方法呢？

提前致谢！

Answer 1

将此代码放入 OnMapReady 方法中：（它会在蓝点中显示您的位置。）

    @Override
    public void onMapReady(GoogleMap googleMap) {
        if (mMap != null) {
            return;
        }

        mMap = googleMap;
        if (mMap == null) {
            return;
        }

        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;
        }
        mMap.setMyLocationEnabled(true);

        mMap.setOnMyLocationChangeListener(new mMap.OnMyLocationChangeListener() {
        @Override
        public void onMyLocationChange(Location location) {
            if(location!=null){
                mMap.addMarker(new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title("Germany"));
                CameraPosition de = CameraPosition.builder().target(new LatLng(location.getLatitude(), location.getLongitude())).zoom(6).bearing(0).build();
                mMap.moveCamera(CameraUpdateFactory.newCameraPosition(de));
            }               
        }
    });
    }

Answer 2

在 onMapReady 方法中替换此代码

@Override
public void onMapReady(GoogleMap googleMap) {

    MapsInitializer.initialize(getContext());

    mGoogleMap = googleMap;
    googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
    mGoogleMap.setMyLocationEnabled(true);
    mGoogleMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
        @Override
        public void onMyLocationChange(Location location) {
            if(location!=null){
                mGoogleMap.addMarker(new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title("Germany"));
                CameraPosition de = CameraPosition.builder().target(new LatLng(location.getLatitude(), location.getLongitude())).zoom(6).bearing(0).build();
                mGoogleMap.moveCamera(CameraUpdateFactory.newCameraPosition(de));
            }               
        }
    });
}

Answer 3

你的问题是你无法让你的 activity 和片段进行通信。实现此目的的一种简单方法是使用库 EventBus ： https://github.com/greenrobot/EventBus

请阅读文档。

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