实施 SetMyLocationEnabled 时不显示“添加权限检查”

Question

我正在尝试在地图顶部获取当前位置图标。但是，当我运行该应用程序时，地图的外观；

另一种情况是我写这行的时候；

 mGoogleMap.setMyLocationEnabled(true);

我无法收到任何“添加权限检查”警告，例如；

。所以我手工写了这些权限。

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)

            if (checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                return;
            }

    }

我不知道这样做与否的正确方法。这是我的完整代码；

    private Activity activity = this;
    ActionBarDrawerToggle drawerToggle;
    DrawerLayout drawerLayout;
    RecyclerView recyclerMenu;
    AdapterMenu obAdapter;
    private Tracker mTracker;
    GoogleMap mGoogleMap;
    GoogleApiClient mGoogleApiClient;

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

        if (googleServicesAvailable()) {

            initmap();
        } else {
            //No google maps layout
        }


    }


    public boolean googleServicesAvailable() {
        GoogleApiAvailability api = GoogleApiAvailability.getInstance();
        int isAvailable = api.isGooglePlayServicesAvailable(this);
        if (isAvailable == ConnectionResult.SUCCESS)
            return true;
        else if (api.isUserResolvableError(isAvailable)) {
            Dialog dialog = api.getErrorDialog(this, isAvailable, 0);
            dialog.show();
        } else
            Toast.makeText(this, "Can't connect to play services", Toast.LENGTH_LONG).show();

        return false;
    }

    private void initmap() {
        MapFragment mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.fragment);
        mapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mGoogleMap = googleMap;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)

                if (checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                    return;
                }

        }
        mGoogleMap.setMyLocationEnabled(true);


    }

    public void geoLocate(View view) throws IOException {
        EditText searchtext = (EditText) findViewById(R.id.editAra);
        String location = searchtext.getText().toString();

        Geocoder geocoder = new Geocoder(this);
        List<Address> list = geocoder.getFromLocationName(location, 1);
        Address address = list.get(0);
        String locality = address.getLocality();

        Toast.makeText(this, locality, Toast.LENGTH_LONG).show();

        double latitude = address.getLatitude();
        double longitude = address.getLongitude();

        goToLocationZoom(latitude, longitude, 15);
    }

    private void goToLocationZoom(double latitude, double longitude, float zoom) {

        LatLng LatLang = new LatLng(latitude, longitude);
        CameraUpdate update = CameraUpdateFactory.newLatLngZoom(LatLang, zoom);
        mGoogleMap.moveCamera(update);
    }
}

Answer 1

如果用户没有授予位置权限，您应该明确请求它（仅适用于 Android M 及更高版本）。然后你应该重写 onRequestPermissionsResult 并管理结果。

这里有一个你想要的工作示例：

public class MainActivity extends FragmentActivity implements OnMapReadyCallback {
private static final String[] LOCATION_PERMISSIONS = {
        Manifest.permission.ACCESS_FINE_LOCATION,
        Manifest.permission.ACCESS_COARSE_LOCATION
};
private static final int LOCATION_PERMISSIONS_REQUEST_CODE = 1;

private GoogleMap mGoogleMap;

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

@Override
public void onMapReady(final GoogleMap googleMap) {
    this.mGoogleMap = googleMap;
    if (hasGrantedLocationPermissions()) {
        showCurrentLocationMapControl();
    } else {
        requestForLocationPermissions();
    }
}

@Override
public void onRequestPermissionsResult(final int requestCode, final @NonNull String[] permissions, final @NonNull int[] grantResults) {
    if (requestCode == LOCATION_PERMISSIONS_REQUEST_CODE) {
        if (grantResults.length == LOCATION_PERMISSIONS.length) {
            for (final int grantResult : grantResults) {
                if (PackageManager.PERMISSION_GRANTED != grantResult) {
                    return;
                }
            }
            showCurrentLocationMapControl();
        }
    }
}

private boolean hasGrantedLocationPermissions() {
    return ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED &&
            ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED;
}

private void requestForLocationPermissions() {
    ActivityCompat.requestPermissions(this, LOCATION_PERMISSIONS, LOCATION_PERMISSIONS_REQUEST_CODE);
}

private void showCurrentLocationMapControl() {
    if (null != this.mGoogleMap) {
        this.mGoogleMap.setMyLocationEnabled(true);
    }
}

}

不要忘记在清单文件中定义所需的权限：

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

Answer 2

// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,Manifest.permission.ACCESS_FINE_LOCATION)
        != PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(thisActivity,Manifest.permission. ACCESS_COARSE_LOCATION)
        != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
            Manifest.permission.READ_CONTACTS)) {

        // Show an explanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.

    } else {

        // No explanation needed, we can request the permission.

        ActivityCompat.requestPermissions(thisActivity,
                new String[]{Manifest.permission.READ_CONTACTS},
                MY_PERMISSIONS_REQUEST_READ_CONTACTS);

        // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
        // app-defined int constant. The callback method gets the
        // result of the request.
    }
}

那么，权限结果

@Override
public void onRequestPermissionsResult(int requestCode,
        String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Do the
                // contacts-related task you need to do.

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }

        // other 'case' lines to check for other
        // permissions this app might request
    }
}