Question

标题可能有点复杂，但问题实际上就像所描述的那样。我试图在片段堆栈中使用谷歌地图片段。当应用程序启动时，用户将看到一个按钮，当用户按下按钮时，当前视图将被替换为地图片段。目前，我能够替换片段，但是当显示地图片段时，视图仍然具有前一片段的按钮。我也试图替换我的应用程序的一个选项卡中的片段。这是我的代码;

地图片段;

public class MapFragment extends Fragment {

    MapView mMapView;
    private GoogleMap googleMap;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.activity_maps, container, false);

        mMapView = (MapView) rootView.findViewById(R.id.mapView);
        mMapView.onCreate(savedInstanceState);

        mMapView.onResume(); // needed to get the map to display immediately

        try {
            MapsInitializer.initialize(getActivity().getApplicationContext());
        } catch (Exception e) {
            e.printStackTrace();
        }

        mMapView.getMapAsync(new OnMapReadyCallback() {
            @Override
            public void onMapReady(GoogleMap mMap) {
                googleMap = mMap;
                try {
                    googleMap.setMyLocationEnabled(true);
                } catch (SecurityException e) {
                    e.printStackTrace();
                }
                // For dropping a marker at a point on the Map
                LatLng sydney = new LatLng(-34, 151);
                googleMap.addMarker(new MarkerOptions().position(sydney).title("Marker Title").snippet("Marker Description"));

                // For zooming automatically to the location of the marker
                CameraPosition cameraPosition = new CameraPosition.Builder().target(sydney).zoom(12).build();
                googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
            }
        });

        return rootView;
    }

    @Override
    public void onResume() {
        super.onResume();
        mMapView.onResume();
    }

    @Override
    public void onPause() {
        super.onPause();
        mMapView.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mMapView.onDestroy();
    }

    @Override
    public void onLowMemory() {
        super.onLowMemory();
        mMapView.onLowMemory();
    }
}

Home Fragment;

public class HomeFragment extends RootFragment {

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

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        // Obtain the shared Tracker instance.

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.home_tab, container, false);

        Button go = (Button)v.findViewById(R.id.btn_go);
        go.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
               // Intent intent = new Intent(getActivity(), MapFragment.class);
                //startActivity(intent);
                enterNextFragment();
            }
        });
        return v;
    }

    @Override
    public void onResume() {

        super.onResume();
    }
    private void enterNextFragment() {
        // Pushing MapView Fragment
        Fragment fragment = Fragment.instantiate(this.getContext(), MapFragment.class.getName());
        FragmentTransaction ft = getFragmentManager().beginTransaction();
        ft.replace(R.id.fragment_mainLayout, fragment);
        ft.commit();
    }

}

地图布局;

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <com.google.android.gms.maps.MapView
        android:id="@+id/mapView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

Home Fragment;

<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=".HomeFragment"
android:background="@android:color/white"
android:id="@+id/fragment_mainLayout">

<!-- TODO: Update blank fragment layout -->


<android.support.v7.widget.AppCompatButton
    android:id="@+id/btn_go"
    android:layout_width="fill_parent"
    android:layout_marginRight="20dp"
    android:layout_marginLeft="20dp"
    android:layout_height="wrap_content"
    android:layout_marginTop="170dp"
    android:text="GO"/>

</FrameLayout>

Answer 1

通常你会想要一个片段与另一个片段进行通信示例根据用户事件更改内容。所有片段到片段的通信是通过相关联的活动。两个碎片永远不应该直接沟通。

您的片段不应该根据the documentation直接进行通信。

如果您已经设法与考虑文档的片段进行通信。然后，您可以使用这种简单的方法来更改和重用任何片段。

在您的主持人活动中：

private void changeFragment(Fragment frag, boolean saveInBackstack) {
    String backStateName = ((Object) frag).getClass().getName();

    try {
        FragmentManager manager = getSupportFragmentManager();

        if (manager.findFragmentByTag(backStateName) == null) {
            //fragment not in back stack, create it.
            FragmentTransaction transaction = manager.beginTransaction();
            transaction.replace(R.id.container, frag, backStateName);

            if (saveInBackstack) {
                Log.d(TAG, "Change Fragment: addToBackTack " + backStateName);
                transaction.addToBackStack(backStateName);
            } else {
                Log.d(TAG, "Change Fragment: NO addToBackTack");
            }

            transaction.commit();
        } else {
            manager.popBackStack();
        }
    } catch (IllegalStateException exception) {
        Log.w(TAG, "Unable to commit fragment, could be activity as been killed in
    }
}

Answer 2

只需在map_layout xml文件的主视图中添加import java.util.Scanner; public class ScannerDemo { public static void main (String [] args) { Scanner sc = new Scanner(System.in); String userName; System.out.println("Enter a number"); int userName = sc.nextInt(); System.out.println("your number is " + userName); System.out.println("enter your next number"); int userName2 = sc.nextInt(); System.out.println("your total is " + (userName2 + userName)); } }

Answer 3

这是解决方案;

Home Fragment;

public class HomeFragment extends RootFragment {
    private LocationManager locationManager;

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

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        // Obtain the shared Tracker instance.
        locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.home_tab, container, false);
        Button go = (Button) v.findViewById(R.id.btn_go);
        go.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getActivity(), MapFragment.class);
                if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
                    //Toast.makeText(getContext(), "GPS is Enabled in your devide", Toast.LENGTH_SHORT).show();
                    startActivity(intent);
                } 
            }
        });
        return v;
    }

    @Override
    public void onResume() {

        super.onResume();
    }
}

MapFragment（现在是fragmentActivity而不是片段）;

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

    MapView mMapView;
    private GoogleMap googleMap;
    // private GoogleMap map;
    private LocationRequest mLocationRequest;
    private GoogleApiClient mGoogleApiClient;
    private Location mLastLocation;
    private Marker marker;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        mMapView = (MapView) findViewById(R.id.mapView);
        mMapView.onCreate(savedInstanceState);

        mMapView.onResume(); // needed to get the map to display immediately

        try {
            MapsInitializer.initialize(this.getApplicationContext());
        } catch (Exception e) {
            e.printStackTrace();
        }

        mMapView.getMapAsync(this);



    }

    @Override
    public void onMapReady(GoogleMap mMap) {
        googleMap = mMap;
        LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        Criteria criteria = new Criteria();
        Location location = null;
        try {
            googleMap.setMyLocationEnabled(true);
            location = locationManager.getLastKnownLocation(locationManager.getBestProvider(criteria, false));

        } catch (SecurityException e) {
            e.printStackTrace();
        }


        if (location != null) {
            googleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), 13));

            CameraPosition cameraPosition = new CameraPosition.Builder()
                    .target(new LatLng(location.getLatitude(), location.getLongitude()))      // Sets the center of the map to location user
                    .zoom(17)                   // Sets the zoom
                    .bearing(90)                // Sets the orientation of the camera to east
                    .tilt(40)                   // Sets the tilt of the camera to 30 degrees
                    .build();                   // Creates a CameraPosition from the builder
            googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
        }
    }
}

Google Map片段显示了上一个片段的元素

3 个答案: