如何在片段中运行此 API？

Question

我只是想按照我在 YouTube (https://www.youtube.com/watch?v=boyyLhXAZAQ) 上找到的教程运行 Google Maps API，出于某种原因，我不知道为什么，但它在主要活动中有效，但我无法获得它在与“fragment_election.xml”相关联的名为“ElectionFragment.java”的片段中工作

是不是跟fragment java类的OnCreate/OnCreateView有关？

ElectionFragment.java

package com.example.fypfinaltrial;


import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Bundle;

import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;

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

import com.google.android.gms.location.FusedLocationProviderClient;
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.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;


/**
 * A simple {@link Fragment} subclass.
 */
public class ElectionFragment extends FragmentActivity implements OnMapReadyCallback {

    Location currentLocation;
    FusedLocationProviderClient fusedLocationProviderClient;
    private static final int REQUEST_CODE = 101;

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



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

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

        fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
        fetchLastLocation();
    }

    private void fetchLastLocation() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{
                    Manifest.permission.ACCESS_FINE_LOCATION}, REQUEST_CODE);
            return;
        }
        Task<Location> task = fusedLocationProviderClient.getLastLocation();
        task.addOnSuccessListener(new OnSuccessListener<Location>() {
            @Override
            public void onSuccess(Location location) {
                if (location != null) {
                    currentLocation = location;
                    Toast.makeText(getApplicationContext(), currentLocation.getLatitude()
                            + " " + currentLocation.getLongitude(), Toast.LENGTH_SHORT).show();
                    SupportMapFragment supportMapFragment = (SupportMapFragment)
                            getSupportFragmentManager().findFragmentById(R.id.google_map);
                    supportMapFragment.getMapAsync(ElectionFragment.this);
                }
            }
        });
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        LatLng latLng = new LatLng(currentLocation.getLatitude(), currentLocation.getLongitude());
        MarkerOptions markerOptions = new MarkerOptions().position(latLng)
                .title("I Am Here");
        googleMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
        googleMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latLng, 5));
        googleMap.addMarker(markerOptions);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissisons, @NonNull int[] grantResults) {
        switch (requestCode) {
            case REQUEST_CODE:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    fetchLastLocation();
                }
                break;
        }
    }
}

这里是 fragment_election.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ElectionFragment">

    <fragment
       android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/google_map"
        android:name="com.google.android.gms.maps.SupportMapFragment"/>
</RelativeLayout>

它与片段中的片段有关吗？

Answer 1

如果你想在片段中实现谷歌地图，那么你必须遵循一些不同的过程，这里是在片段中实现谷歌地图的方法。

在 XML 文件中

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

在JAVA文件中

 public class ElectionFragment extends Fragment implements OnMapReadyCallback {
    MapView mapView;
    GoogleMap mMap;
    Marker marker;

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

        View view =  inflater.inflate(R.layout.fragment_election, container, false);
        mapView = view.findViewById(R.id.fake_map);
        mapView.getMapAsync(this);
        mapView.onCreate(savedInstanceState);
        mapView.onResume();// needed to get the map to display immediately
        try {
            MapsInitializer.initialize(getActivity().getApplicationContext());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return view;
    }



    @Override
    public void onMapReady(GoogleMap googleMap) {
        this.mMap = googleMap;
        LatLng latLng = new LatLng(43.237601,76.884760);
        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(latLng);
        markerOptions.title("");
        markerOptions.icon(BitmapDescriptorFactory.fromResource(R.drawable.marker_icon));
        markerOptions.getPosition();
        marker = mMap.addMarker(markerOptions);
        CameraPosition cameraPosition = CameraPosition.builder()
                .target(latLng)
                .zoom(17)
                //              .bearing(20)
                .build();
        mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition), 2000, null);
    }

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

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

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

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

    }