问题描述
package com.example.myapplication.ui.home;
import android.Manifest;
import android.annotation.SuppressLint;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.location.Location;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.app.ActivityCompat;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.Observer;
import androidx.lifecycle.viewmodelProvider;
import androidx.lifecycle.viewmodelProviders;
import com.example.myapplication.R;
import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationResult;
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.MapStyleOptions;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.karumi.dexter.Dexter;
import com.karumi.dexter.PermissionToken;
import com.karumi.dexter.listener.PermissionDeniedResponse;
import com.karumi.dexter.listener.PermissionGrantedResponse;
import com.karumi.dexter.listener.PermissionRequest;
import com.karumi.dexter.listener.single.PermissionListener;
public class HomeFragment extends Fragment implements OnMapReadyCallback {
private GoogleMap mMap;
private Homeviewmodel homeviewmodel;
// Location
private FusedLocationProviderClient fusedLocationProviderClient;
private LocationRequest locationRequest;
private LocationCallback locationCallback;
SupportMapFragment mapFragment;
@Override
public void onDestroy() {
fusedLocationProviderClient.removeLocationUpdates(locationCallback);
super.onDestroy();
}
public View onCreateView(@NonNull LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
homeviewmodel = new viewmodelProvider(this).get(Homeviewmodel.class);
View root = inflater.inflate(R.layout.fragment_home,container,false);
init();
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
mapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
return root;
}
private void init() {
locationRequest = new LocationRequest();
locationRequest.setSmallestdisplacement(10f);
locationRequest.setInterval(50000);
locationRequest.setFastestInterval(3000);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationCallback = new LocationCallback() {
@Override
public void onLocationResult(LocationResult locationResult) {
super.onLocationResult(locationResult);
LatLng newposition = new LatLng(locationResult.getLastLocation().getLongitude(),locationResult.getLastLocation().getLatitude());
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(newposition,18f));
}
};
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Check Permission
Dexter.withContext(getContext())
.withPermission(Manifest.permission.ACCESS_FINE_LOCATION)
.withListener(new PermissionListener() {
@SuppressLint("MissingPermission")
@Override
public void onPermissionGranted(PermissionGrantedResponse permissionGrantedResponse) {
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.getUiSettings().setMyLocationButtonEnabled(true);
mMap.setonMyLocationButtonClickListener(new GoogleMap.OnMyLocationButtonClickListener() {
@Override
public boolean onMyLocationButtonClick() {
fusedLocationProviderClient.getLastLocation()
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(getContext(),""+e.getMessage(),Toast.LENGTH_SHORT).show();
}
})
.addOnSuccessListener(new OnSuccessListener<Location>() {
@Override
public void onSuccess(Location location) {
}
})
}
});
}
@Override
public void onPermissionDenied(PermissionDeniedResponse permissionDeniedResponse) {
Toast.makeText(getContext(),"Permission"+permissionDeniedResponse.getPermissionName()+""
+"was denied!",Toast.LENGTH_SHORT).show();
}
@Override
public void onPermissionRationaleShouldBeShown(PermissionRequest permissionRequest,PermissionToken permissionToken) {
}
}).check();
try {
boolean success = googleMap.setMapStyle(MapStyleOptions.loadRawResourceStyle(getContext(),R.raw.uber_maps_style));
if(!success){
Log.e("ERROR","Style parsing error");
}
}catch(Resources.NotFoundException e){
Log.e("ERROR",e.getMessage());
}
}
}
我是编程的新手。
在线
如果（ActivityCompat.checkSelfPermission（this，Manifest.permission.ACCESS_FINE_LOCATION）！= PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission（this，Manifest.permission.ACCESS_COARSE_LOCATION）！= PackageManager.PERMISSION_GRANTED）
必需类型：上下文 提供：PermissionListener 这应该换成什么，但我不知道是什么。请帮助
解决方法
ActivityCompat.checkSelfPermission()接受两个参数，其中第一个是主要活动的上下文。
由于您是从权限侦听器回调内部调用方法的，因此关键字this指向PermissionListener对象，而不是上下文。您应该使用主要活动的上下文代替this关键字。
由于您位于片段中，因此需要获取主要活动的上下文。可以使用onAttach回调提供的Context参数来完成此操作。
public class HomeFragment extends Fragment implements OnMapReadyCallback {
Context ctx;
@Override
public void onAttach(Context context) {
super.onAttach(context);
ctx=context;
}
//Other stuff
}
将上下文对象（ctx）传递到ActivityCompat.checkSelfPermission()方法。