java - Androidx 的 fragment 中的 map 实现

Question

这个问题已经有答案了:

What does a "Cannot find symbol" or "Cannot resolve symbol" error mean? (18 个回答)

已关闭 3 年前。

该错误与 getMapAsync() 函数有关。这是导致错误的主要原因。我正在尝试在此 fragment 中实现 getMapAsync() 。错误是:

error: cannot find symbol method getMapAsync(GenHomeFragment)

我在互联网上搜索但没有找到合适的解决方案，因为这个解决方案不适用于AndroidX，所以我无法解决这个问题。

fragment 如下:

package e.user.madiambu;



import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Build;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.app.ActivityCompat;
import androidx.fragment.app.Fragment;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.FragmentManager;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;




import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.location.LocationListener;

import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationRequest;
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.MapFragment;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;


/**
 * A simple {@link Fragment} subclass.
 */
public class GenHomeFragment extends Fragment implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener


{

    private GoogleMap mMap;
    private GoogleApiClient googleApiClient;
    private LocationRequest locationRequest;
    private Location lastLocation;
    private Marker currentUserLocationMarker;

    private static final int Request_User_location_code=99;


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


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {


        // Inflate the layout for this fragment
       View view=inflater.inflate(R.layout.fragment_gen_home, container, false);


        if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.M)
        {
            checkUserLocationPermission();
        }
        FragmentManager fm = getFragmentManager();
        Fragment mapFragment = fm.findFragmentById(R.id.googleMap);

        if (mapFragment != null) {
            mapFragment.getMapAsync(this);
        }

        return view;
    }



    @Override
    public void onMapReady(GoogleMap googleMap) {

        mMap = googleMap;


        if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_FINE_LOCATION)== PackageManager.PERMISSION_GRANTED)
        {
            buildGoogleApiClient();
            mMap.setMyLocationEnabled(true);
        }

    }

    public boolean checkUserLocationPermission()
    {
        if(ContextCompat.checkSelfPermission(getActivity(),Manifest.permission.ACCESS_FINE_LOCATION)!=PackageManager.PERMISSION_GRANTED)
        {
            if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(),Manifest.permission.ACCESS_FINE_LOCATION))
            {
                ActivityCompat.requestPermissions(getActivity(),new String[]{Manifest.permission.ACCESS_FINE_LOCATION},Request_User_location_code);
            }
            else
            {
                ActivityCompat.requestPermissions(getActivity(),new String[]{Manifest.permission.ACCESS_FINE_LOCATION},Request_User_location_code);
            }

            return false;
        }

        else
        {
            return true;
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode)
        {
            case Request_User_location_code:
                if (grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED)
                {
                    if (ContextCompat.checkSelfPermission(getActivity(),Manifest.permission.ACCESS_FINE_LOCATION)==PackageManager.PERMISSION_GRANTED)
                    {
                        if (googleApiClient==null)
                        {
                            buildGoogleApiClient();//Create new Client.....
                        }
                        mMap.setMyLocationEnabled(true);
                    }
                }

                else
                {
                    Toast.makeText(getActivity(),"permission Denied...", Toast.LENGTH_SHORT).show();
                }
                return;
        }
    }


    protected synchronized void buildGoogleApiClient()
    {
        googleApiClient=new GoogleApiClient.Builder(getActivity())
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
        googleApiClient.connect(); //Connected Google api client.....
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {

        locationRequest=new LocationRequest();
        locationRequest.setInterval(1100);
        locationRequest.setFastestInterval(1100);
        locationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);

        if (ContextCompat.checkSelfPermission(getActivity(),Manifest.permission.ACCESS_FINE_LOCATION)==PackageManager.PERMISSION_GRANTED)
        {
            LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient,locationRequest,this);
        }

    }

    @Override
    public void onConnectionSuspended(int i) {

    }

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

    }



    @Override
    public void onLocationChanged(Location location) {

        lastLocation=location;

        if (currentUserLocationMarker !=null){
            currentUserLocationMarker.remove();
        }

        LatLng latLng=new LatLng(location.getLatitude(),location.getLongitude());

        MarkerOptions markerOptions=new MarkerOptions();
        markerOptions.position(latLng);
        markerOptions.title("User Current Location");//Show user current location maker....
        markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
        currentUserLocationMarker=mMap.addMarker(markerOptions);

        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
        mMap.animateCamera(CameraUpdateFactory.zoomBy(12));

        if(googleApiClient !=null)
        {
            LocationServices.FusedLocationApi.removeLocationUpdates(googleApiClient,this);
        }


    }
}

我的 xml 如下:

<?xml version="1.0" encoding="utf-8"?>
<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=".GenHomeFragment">

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

</FrameLayout>

Answer 1

com.google.android.gms.maps.MapView 不是一个 fragment ，它是一个 View 。这里您没有使用具有谷歌地图的 fragment ，例如

<fragment
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/fragment_view_map"
        class="com.google.android.gms.maps.MapFragment"></fragment>

当您使用mapView时，请按照以下步骤操作:

private MapView mMap;

在onCreateView中

mMap = findViewById(R.id.googleMap)

然后你就可以使用

mMap.getMapAsync(this)