Question

大家晚上好，我想告诉你我的问题，所以我希望我的android中的google map中显示带到我当前位置的按钮，但是当我在真实电话中尝试该按钮时（三星SM-J730G android 7.0 api 24）小按钮没有出现（我没有在模拟器中尝试过，原因是我也无法正常工作）。所以我想知道是什么问题，请朋友在这里帮助我，谢谢您的帮助：

public class MapFragment extends Fragment implements View.OnClickListener {


private View rootView;
private MapView mapView;
private GoogleMap mMap;
private FloatingActionButton fab;


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


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    this.rootView = inflater.inflate(R.layout.fragment_map, container, false);
    this.fab = (FloatingActionButton) rootView.findViewById(R.id.fab);
    return rootView;
}


 @Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    this.fab.setOnClickListener(this);
    this.mapView = (MapView) this.rootView.findViewById(R.id.map);
    if (mapView != null) {
        this.mapView.onCreate(null);
        this.mapView.onResume();
        this.mapView.getMapAsync(new OnMapReadyCallback() {
            @Override
            public void onMapReady(GoogleMap googleMap) {
                mMap = googleMap;
                if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    return;
                }
                mMap.setMyLocationEnabled(true); //I DONT KNOW WHY IT DOES NOT WORK


                  }
              });

    }



    super.onViewCreated(view, savedInstanceState);
}

哦，我对它进行了调试，并且

 if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    return;   //is entrying here and i donw know why if i have the perssions in the manifest the accces_fine_location and acces_coarse_location
                }
                mMap.setMyLocationEnabled(true);   


please somebody help me thanks you

Answer 1

您仅检查了运行时权限，如果未提供，则未请求该权限。更新以下代码，然后onRequestPermissionsResult检查是否从此处设置了mMap.setMyLocationEnabled(true);

     @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        this.fab.setOnClickListener(this);
        this.mapView = (MapView) this.rootView.findViewById(R.id.map);
        if (mapView != null) {
           his.mapView.getMapAsync(new OnMapReadyCallback() {
                @Override
                public void onMapReady(GoogleMap googleMap) {
                    mMap = googleMap;
                    if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

  ActivityCompat.requestPermissions(context, new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 101);
                        return;
                    }
                    mMap.setMyLocationEnabled(true); //I DONT KNOW WHY IT DOES NOT WORK


                      }
                  });

        }

关于权限结果

@Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if(requestCode == 101) {
  f (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
mMap.setMyLocationEnabled(true);  }
  }                 
}

Answer 2

此外，它有助于确保在使用地图时始终启用GPS。

我在android studio中位置的问题

2 个答案: